Engineering of functional materials with chemical coating methods

Resume : Chemical solution methods for thin-film deposition constitute an affordable alternative to high-vacuum physical technologies, like Sputtering, Pulsed Laser Deposition (PLD) or Molecular BeamEpitaxy (MBE). Particularly, chemical methods have proven to be very suitable for producing functional films over large areas, especially in the relatively thick range, from >100 nm to microns. Also, their versatility to synthesize different types of materials, i.e. carbides, silicides, pnictides,oxides or chalcogenides, make them particularly attractive for a wide range of applications and studies. However, problems with surface/interface roughness, control of stoichiometry in multi-cationic or precisely-doped materials, and a lack of accurate control of the thickness in the thinlimit range (< 20 nm) has weighed the competitiveness of these processes against high vacuumphysical methods. This is particularly true in the case of multicationic oxide thin-films, which have experienced a frantic research activity in recent years associated with phenomena of interaction across atomically sharp interfaces. In this talk we will descrbie Polymer Assisted Deposition (PAD), as a suitable chemical-solution method for the fabrication of high-quality epitaxialthin-films, particularly for oxides. After discussing the most relevant chemical aspects of the method, we will present the results obtained in a variety of structural phases, like perovskites, spinels, garnets, etc, to demonstrate the hability of PAD to produce oxide thin-films with the quality required for fundamental studies and applications.

Resume : Chemical solution deposited (CSD) YBa2Cu3O7-x (YBCO) nanocomposite thin films hold great potential for high magnetic field applications. Here we present a novel route to prepare superconducting nanocomposite films using preformed nanoparticles from colloidal solution which enables tight control of composition, size and concentration and therefore facilitates the tailoring of nanocomposite structure and pinning properties. Two types of preformed unreactive nanoparticles, BaZrO3 (BZO) and BaHfO3 (BHO), with nanoparticle size 5-10 nm, are successfully introduced within YBCO matrix. We find that preformed BMO nanoparticles allow a record load of 20 mol% in epitaxial YBCO leading to Jc@ 77K of 5MA/cm2. Also, a flash heating growth process, which shows high compatibility with the reel-to-reel continuous industrial production, has been applied and found to be crucial to effectively modify the concentration of structural defects and nanostrain and thus, further increase the vortex pinning properties. We have used advanced x-ray diffraction characterization, scanning transmission electron microscopy and transport measurements to deeply evaluate the structural defect-vortex pinning relationship for CSD- YBCO nanocomposites. Therefore, solution derived YBCO nanocomposites from preformed nanoparticles offer great opportunities for high performance coated conductors.

Resume : Ferroelectric perovskite oxide (FEPO) based photovoltaic (PV) cells arise as an innovative and promising alternative to current photovoltaic technology. Enhancing the light absorption in FEPO materials by judicious engineering of the band gap offers unprecedented opportunities to build PV devices with increased power conversion efficiency. Multiferroic Bi-based perovskite oxides such as BiFeO3 (BFO) are focusing great deal of attention because ferroelectricity, magnetism and light absorption phenomena can be coupled leading to new challenges and avenues in photovoltaics. Here, we take advantage of the chemical solution deposition (CSD) technique to study the stabilization of new compositions based on BiFeO3 for visible-light absorption. The influence of processing temperature, time and atmosphere has been investigated on the formation of epitaxial BiFe1-xCoxO3 (BFCO) thin films. Here it is presented for the first time the preparation of stable BFCO films with bandgaps down to 1.4 eV. Also, controlled Bi substitution by rare earth cations (i.e. La3+) has been achieved in BFCO films, offering an effective strategy to further improve film purity, epitaxy and surface morphology with unaltered physical properties. Finally, the optimized CSD processing conditions for the BFCO thin films have been proved compatible on several oxide bottom electrodes: La0.7Sr0.3MnO3 and ITO layers, being thus a promising strategy for all-oxide photovoltaics.

Resume : Functional thin films based on complex oxides show crystallization temperatures usually over 600 ºC. This has historically excluded them from a direct integration into flexible electronic systems, since their processing temperatures are several hundred degrees above the values that polymeric substrates can withstand (≤350 ºC). Novel deposition processes have recently emerged enabling the growth of metal oxide layers directly on plastic. Among them, UV-assisted chemical solution deposition is a low-temperature method that scales easily to large areas and allows for the engineering of functional materials into a new generation of low-cost flexible devices.1-3 Here, the main steps of this method will be described making particular emphasis on the synthesis of novel photosensitive solutions (modified metal alkoxides, charge-transfer metal complexes or structurally designed molecular compounds) and the reactions promoted by UV light (photochemical cleavage, ozonolysis, condensation or photocatalysis). Relevant examples of flexible thin films based on photoferroic BiFeO3 and ferroelectric Pb(Zr,Ti)O3 systems will illustrate the most recent achievements by this novel deposition process. [1] Bretos et al., Chem. Soc. Rev., 2018, DOI: 10.1039/c6cs00917d. [2] Bretos et al., Adv. Mater., 2015, 27, 2608-2613. [3] Bretos et al., Adv. Mater., 2014, 26, 1405-1409. Supported by Spanish Project MAT2016-76851-R and Fundación General CSIC (ComFuturo Programme).

Resume : The interest to increase the performances of solid-state memories has led to the development of new types of storage mechanisms. Alternatives to the transistor-based memories are now considered as potential candidates for both long-term memory storage (ReRAM) and brain-like computing (neuristors). In this project, lanthanum-nickelates are investigates as a model material to better understand a particular type of resistive-switching (RS) mechanism: the valence-change mechanism. This mechanism explains the change in resistance by a local oxidation (reduction) of the active material under an electric-field induced oxygen accumulation (depression). La2NiO4 being a mixed-ionic electronic conductor is known for its high oxygen mobility, potentially increasing the control over the RS phenomenon. Nevertheless, the oxygen mobility of La2NiO4 is strongly affected by its crystallinity and crystal-orientation. This work is focused on the deposition optimization of LaNiO3 as template electrode for the growth of oriented La2NiO4. The material was grown on SrTiO3 and LaAlO3 single crystals using pulsed-injection metal-organic chemical vapour deposition (pi-MOCVD). The formation of NiO or La2O3 precipitates depending on the deposition parameters will be shown together with how substrate-induced strain affects the crystal structure of LaNiO3. Results obtained with thin-films grown by Pulsed Laser Deposition (PLD) will also be presented for comparison.

Resume : In the recent years,there has been an exponential growth of research activities in the production of new and more efficient photovoltaic(PV) devices.One strategy to enhance the efficiency of PV devices is to collect the radiation energy outside the absorption range of the photoactive material by shifting its energy to a more suitable optical region.In particular,the most efficient hosts for energy up-conversion consist of alkaline fluoride matrices,as CaF2 and NaYF4,doped with Ln3+ions,such as Yb3+/Er3+ and Yb3+/Tm3+. In the present study,starting from fluorinated metalorganic β-diketonate compounds we report the synthesis of Ln-doped fluoride thin films through two different chemical approaches:Metal-Organic Chemical Vapor Deposition(MOCVD) technique,applied to the deposition of CaF2:Yb3+/Er3+,and a combined sol-gel/spin-coating technique for the deposition of β-NaYF4:Yb3+/Er3+. Both chemical approaches have the advantage of being very reliable and reproducible methods for the fast production of films with high uniformity degree over large areas.The fluorinated metal precursors act as a single-source in both processes,and an accurate control of the process parameters allows the optimization of the doped CaF2 and NaYF4 films.X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis have been used to characterize the deposited films.Spectroscopic properties in the visible and near infrared regions upon laser excitation at 980nm have been investigated.

Resume : Demands for piezoelectric thin films have been sustainably increased since they aresuitable for various devices such as actuators, sensors, and energy harvesters. Unfortunately, Pb(Zr,Ti)O3 (PZT)-based thin films, which possess excellent piezoelectric properties, canraise the environmental problem because it contains more than 60 wt% of PbO.Candidates forlead-free ceramics like BaTiO3, bismuth layered compound and (Na,K)NbO3 also have limitation because of the insufficient performanceandthe high growth temperatures. New type of lead-free piezoelectric superlattice thin films, which consist of the two different paraelectric oxide nanosheets, have been fabricated using Langmuir-Blodgett (LB) method and these piezoelectric superlattice thin films showed the promising piezoelectric properties. However, LB deposition method is difficult to be utilized in industrial area. In this research, a new type of the lead-free piezoelectric thin film consisting of Sr2NaNb4O13 and TiNbO5 oxide nanosheets were fabricated at room temperature using the electrophoretic method. Moreover, the structural and piezoelectric properties of this lead-free piezoelectric thin films were investigated. This piezoelectric film showed the promisingferroelectric and piezoelectric properties of Pr = 7.3 μC/cm2 and d33 = 126 pm/V with the low dielectric low (< 0.05) and the leakage current density (<1.0× 10-6 A/cm2 at 0.3 MV/cm). Moreover, the electrophoretic deposition method is very simple and thus it can be easily used in the industrial area. In this work, the detailed growth processes and their effects on the electrical properties of the lead-free piezoelectric thin film will be presented.

Resume : Electrodeposition is an efficient and economically beneficial surface engineering technique. The objective of the present investigation is to electrodeposit a functionally graded Cu-SiC coating on Cu substrate. By varying current density (50-200mA/cm2), three layers (10 microns each) of pure Cu are deposited in a manner that there is a gradual variation in grain size from coarse to fine along the thickness. This is followed by two layers Cu-SiC nanocomposite coating (10 microns each) with a gradual increment (2 vol%-7vol%) of SiC nanoparticles with a change in bath agitation (350-450 rpm) at 200mA/cm2. The reinforcing phase is used to refine the microstructure and impart hardness to the coating. The functionally graded Cu-SiC coating possesses high hardness (3.4 GPa), and low surface roughness (2.9μm) without a significant change in the electrical resistivity (4.1μΩ/m) as compared to bulk Cu (1.6 μΩ/m). The electrical resistivity of the coating is affected mainly by second-phase incorporation, but the values obtained are in the allowable range required for electrical applications. Keywords Functionally graded material, Electrodeposition, SiC, Electrical contact

Resume : Stainless Steel (SS) alloys are widely used in many applications for their excellent corrosion and wear resistances as well as their mechanical properties. Specifically, AISI 304 (18Cr-10Ni) and 316L SS are extremely important in biological and medical areas. In this study, SS-like FeCrNi is electroplated from an ’environmentally green’ Cr(III)-based electrolyte containing glycine as Cr(III) complexing agent. We report results from corrosion, magnetic and bio-compatibility tests for electrodeposited FeCrNi films compared with metallurgical SS [1]. Anodic linear sweep polarization scans with cathodic pre-treatment in 0.5 M sulfuric acid solution were performed. Amorphous electroplated FeCrNi film depicts excellent corrosion resistance; specifically the corrosion behaviour of electrodeposit with Cr23.6wt% is comparable to AISI 304 and 316L SS. At the contrary of metallurgical austenitic SS, electrodeposits of FeCrNi are soft-magnetic. Saturation magnetisation is dependent on the chromium content: from almost zero magnetisation (Cr33.7wt%) to approximatively 600 emu/cm3 (Cr3.5wt%). This mechanism can be explained with exchange interaction mechanisms of both Fe-Fe and Fe-Cr. In addition, cytotoxicity tests were performed on electroplated FeCrNi, AISI 304 and 316L, showing similar cell adhesion and a comparable cell death among the three samples. Indeed, these properties show a great potential for creating micro-nano components specific for biomedical and micro-robotics applications. [1] M. Hasegawa, E. Bertero et al, Electrodeposition of amorphous Fe-Cr-Ni stainless steel alloy with high corrosion resistance, low cytotoxicity and soft magnetic properties, Surface & Coatings Technology, 2018 (in-press)

Resume : In this work, methods for controlled electrophoretic deposition (EPD) of nanosized semiconductors (such as Zinc sulfide, ZnS) and co-deposition with carbon materials (such as modified Vulcan XC 72R) in combination with different salts are described for the first time. A strong interest is in the research and fabrication of nanocatalysts in carbon matrices which may find applications in fuel cells, photovoltaic cells, photocatalytic or antibacterial applications. By modifying the surface charge of the carbon materials with oxidating agents like nitric acid (HNO3) and the addition of different salts e.g. Al(NO3)3 or Y(NO3)3, the zeta potential could be controlled in sign and magnitude, in aqueous solutions as well as in alcohols like 2-propanol. ZnS with cysteamine or mercaptoethanol as surface ligand served as partner in co-deposition. It was observed that controlling variables in the pretreatment to the deposition process carry a high potential to modify the structure and the composition of the co-deposits. 2-propanol with ZnS showed the best results considering the deposited mass in combination with Al3+, Y3+ or Mg2+ in solution. In combination with oxidized Vulcan XC 72R it was possibile to use anodic and cathodic deposition processes as well. This work focused on the different fabrication steps to create stable electrode structures and will show deposition by modifiying the surface charge of the semiconductor and carbon components with the use of different salts.

Resume : Metal-organic frameworks (MOFs) are an intriguing class of porous crystalline materials with record internal surface areas. There is tremendous potential for integrating MOFs into microelectronics, e.g. as active sensor coatings or low-k dielectrics.[1] A key enabling step in leveraging the properties of MOFs in microelectronics will be the development of robust thin film deposition methods. Thus far, typical procedures for the deposition of MOF thin films are incompatible with microelectronic fabrication because of corrosion and contamination issues. We recently demonstrated chemical vapor deposition (CVD) of MOF thin films.[2] The MOF-CVD process allows conformal growth of thin films and extends MOF processing to one of the most commonly used techniques in thin film research and manufacturing. Two important challenges were tackled to realize this process: vapor phase supply of precursors and crystallization at the vapor-solid interphase. To our knowledge, this is the first vapor phase process for conformal film deposition of a crystalline and microporous network material. Future directions and potential applications of MOF-CVD coatings will be discussed. References: [1] Stassen, I., Burtch, N., Talin, A. A., Falcaro, P., Allendorf, M. D. & Ameloot, R. (2017) Chem. Soc. Rev. 46, 3185–3241. [2] Stassen, I., Styles, M., Grenci, G., Van Gorp, H., Vanderlinden, W., De Feyter, S., Falcaro, P., De Vos, D. E., Vereecken, P. & Ameloot, R. (2016). Nature Materials, 15, 304–310.

Resume : A suspension of poly(methyl methacrylate) PMMA polymer beads is used as an unique templating agent for forming a scaffolded layer of TiO2 with a control of porosity size by molding process. The goal of this work is to prepare a TiO2 n-type semiconductor porous film to promote the growing large crystals hybrid of lead halide perovskite for a photovoltaic application and enhance interface quality and reduce defects. Moreover in order to probe an enhancement of the scaffolded layer conductivity a sol-gel mixture of titanium and tin in propionic acid was successfully used and deposited by spin-coating technique. This process using polymer beads molding is carried out essentially by a chemical way. SEM/EDX on resulting samples show that a large pore size (up to 100 nm) scaffold layer can be prepared according to the beads diameter (from 100 nm to 800 nm). The XRD patterns correspond to the anatase phase for TiO2 and the casserite phase for SnO2. This two phases separation occurs on several morphological way from perfect mixture of TiO2 and SnO2 nanocrystal surrounding the porosity to a mixture of large SnO2 spherical particles with TiO2 nanocrystal constituting the voids walls. The study is focused essentially on morphology analyses of the porous layers for different preparation conditions and not on complete cells in the aim to demonstrate a simple and cheap way to obtain a porous film of n-type semi-conductor by sol-gel process. We also intend to modify the conductivity of moulded scaffold using Ti-Sn mixed sol-gel solution as TiO2–SnO2 moulding precursors.

Resume : The study is devoted to the development of methods for the 2D and 3D oxide nanostructures synthesis and additional methods for their chemical and structural modification with an aim to create new functional nanomaterials. The layered rare-earth hydroxides (LRHs) that have been discovered recently represent a new class of 2D inorganic materials. Due to their anion-exchange and exfoliation ability layered rare-earth hydroxide can be assembled in 3D composite bulk material containing inorganic rare-earth host and organic guest. These materials currently attract an attention due to their unusual properties, combining features of host and guest species. The most promising LRH applications include the design of luminescent materials and biomaterials. Development of the methods for synthesis 3D nanostructures based on alumina oxyhydroxides, as well as the model proposed for quantitative description of the chemical and structural changes upon annealing at 20 - 1700 °C, led to the laboratory technology allowing to obtain monolithic 3D materials having wide properties range: density of 0.03 – 2.5 g/cm3, open porosity 99.3-25% and specific surface from 300 to 1 m2/g. The surface of the porous monolith can have the composition AlOx(OH)y or SiOx, depending on the task for further chemical modification. Using various methods of chemical adsorption and impregnation, new 3D nanomaterials were obtained: porous spinel MgAl2O4 with the grain size ~10 nm, composites consisting of Al2O3 fibrils network and embedded TiO2 particles with the size from 3 to 10 nm, membranes for superprotonics fuel cells, hybrid 3D nanostructures phthalocyanine-oxide with sensing functions etc. Developed functional 3D materials can be applied in nanoelectronic, photonics, optoelectronics and sensor devices as well as in energy, medicine and environmental protection.

Resume : Colloidal crystals with hexagonal closed packed (HCP) ordering can be obtained on a planar surface by simple spin coating technique, in presence of trace amount of surfactant. By spin coating on a topographically patterned substrate we can also obtain ordered colloidal structures with non-HCP ordering. It is however not possible to obtain a non-HCP ordering on a flat substrate without any chemical or topographic patterning. We have developed a method by which we can overcome this problem, by fabricating the array on a patterned UVO degradable polymer layer and subsequently transfering the array on to another substrate. The flexible nature of the master makes it possible to transfer the array on to non-planar substrates. Our proposed method allows the colloidal structures to be transported across substrates irrespective of their surface energy, wettability or morphology. The transmittance data of the transferred non-HCP colloidal arrays on glass show wide-spectrum anti-reflectivity, yielding about 99.5% transmission over the entire spectral region between 450 and 1700 nm. Reflectance of glass is also reduced to 3.3% over the entire spectral region.

Resume : Researches and innovations in the field of composite materials science has led to the development of a wide variety of multifunctional materials, that over the years, have expanded their applicability in various technological sectors such as aerospace, nuclear technology, biomedicine, optoelectronics, automotive and construction etc. The main objective of the paper consists in emphasising the influence of Y2O3 particles in selected polymer matrix, in order to obtain composite materials suitable for applications as thin films on various nonconventional substrates. Composites materials were synthesized by dispersing of yttrium oxide powder (Y2O3) in matrix of polyvinylidene fluoride (PVDF) in the presence of N-methyl-pyrrolidone (NMP) solvent. In order to determine the distribution degree and the compatibility of the dispersed phase of Y2O3 powder with the polymer matrix, two priority stages of the technological flow were approached by mechanical mixing, followed by ultrasonication. Also, the dispersed phase quantity and the process parameters were optimized. Subsequently, the main components (dispersed phase, polymer matrix) and Y2O3-PVDF composites have been investigated morphologically and structurally, through Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). FTIR spectra of the composite confirm the appearance of the peaks attributed to α and β forms from PVDF and afferent solvents, suggesting the total incorporation of Y2O3 particles in polymer matrix. The XRD spectra show that the characteristics of the significant phases of Y2O3 and PVDF coexist in the Y2O3-PVDF composite. SEM microstructural analysis indicates an interpenetration of the characteristic particles of disperse phase with size and spherical phase, but with the formation of agglomerates of varying size. Based on the results, it is highlighted that the Y2O3-PVDF composites materials may have a significant impact on their functional applications in the development of coating materials.

Resume : The development of thermostable insulators for high-performance electric devices such as electric vehicle motors, for example, have been becoming important recently in terms of sustainable engineering. Electrodeposition coating technique is one of the key steps for developing those high-performance devices because the devices with complicated shapes cannot be coated with conventional techniques. We have developed novel polyimides which have pendant dimethylaminobenzoic groups as cationic moieties after neutralization by an acid. This polyimide is highly soluble in several solvents and its nano-sized particles are easily prepared by the addition of poor solvent, whose diameters are of 200 nm and zeta potentials are of 20mV. Electrodeposition coating was successfully performed on copper plates as electrodes with effective voltage of 10V for 10 minutes. The thickness of the coated polyimide layer was 158µm and the 10% weight loss temperature was as high as 270℃. This materials are advantageous in regard to the capability of coating on copper substrates, and so they should be important materials for manufacturing various high performance electric devices of next-generation.

Resume : Recently, triboelectricity has been widely adopted to develop energy harvesting devices, sensors, and various functional materials. Since triboelectric charging characteristics of the material are determined by material's own intrinsic property, it is difficult to change its original triboelectric property into different one. Therefore, there is a need to develop a simple and easy functionalization method for inducing various triboelectric properties. Among its potential application, triboelectric nanogenerators (TENGs) have been highlighted as a power source for small electronic devices thanks to their relatively simple fabrication and integration with existing device structures. To increase their output power to a level sufficient for small electronic device, considerable efforts have focused on improving their output power. So far, different surface patterning methods, dielectric constant tuning, and device structures have been employed. However, these approaches are relatively complicate and the performance of TENGs is still limited by intrinsic properties of materials used. In this work, we introduce a simple and effective way to tune the triboelectric charging sequence by adopting atomic level chemical surface functionalization. To this end, the synthetic halogenated (Cl, F, and Br)-molecules were functionalized onto polyethylene terephthalates (PETs) to render negative charging surface. For the triboelectrically positive side, on the other hand, the surfaces of PETs were functionalized using several aminated-molecules. Using Kelvin probe microscopy, electrometer, and density functional calculation, thorough investigation has been made to understand the charging behavior of functionalized surfaces. Our results show that wide spectrum of triboelectric charging can be clearly formed by the proposed methods. Noticeably, the TENGs with functionalized using the pair (Cl-PET:PEI(b)-PET) exceed the output voltage of ~520 V and current density of ~110 mA/m2, corresponding power density of ~55 W/m2, which is one of the highest values reported to date. Besides, by providing wide choices of surface functionalization, friction surface can be rendered to have different triboelectric properties, allowing to adopt this technique to develop triboelectric sensors. This works introduced the simple chemical surface method, which can be adopted for developing energy harvesting devices and sensors based on the triboelectric effect.

Resume : Black phosphorus (BP), the most stable allotrope of phosphorus, is a material stacking individual atomic layers together through van der Walls interactions. The band gap of BP is tunable from 0.3eV for bulk BP to 2.0eV for phosphorene (monolayer BP) depending on the number of stacked layers. Two-dimensional black phosphorus (phosphorene) dispersed in a solution is obtained by the solvent exfoliation. Among various solvents, N-methylpyrrolidone (NMP) is found to provide stable and highly concentrated BP dispersions. Due to its instability under ambient conditions, however, the deposition options are limited for the fabrication of optoelectronic devices. Black phosphorous thin films were deposited on the substrates using an inkjet printing method. Physical properties of the printed films were systematically characterized by atomic force microscope (AFM), scanning electron microscopy (SEM), photoluminescence(PL), transmission electron microscope (TEM) and Raman spectroscopy. In this study, the stable, highly concentrated, and electronic-grade phosphorous thin films were successfully deposited by combining the solvent exfoliation with the ink-jet printing deposition method. Considering our analytical results obtained in this study, the black phosphorene prepared in this study could be applied to large-area, high-performance phosphorene devices.

Resume : Many industries are focused on the nano particle metallic inks for the fabrication of electronic devices. silver ink is a typical metallic ink having high conductivity and thermal stability. However, there is a limitation to use it in the fabrication due to its high material cost. Copper is considered as a substitute material for silver, but copper ink has an oxidation issue under atmospheric conditions. Cost effective, highly conductive and oxidation-free copper nano particle ink was synthesized in this study. Copper complexes and copper nano particles were used in the synthesis to prevent its oxidation. Expanding its application to various substrates, the synthesized nano particles were thermally treated at relatively low temperatures in the range of 50~400℃. The prepared copper ink was printed on the silicon substrates and the printed films were then characterized. Each particle of copper complexes and copper nano particles was analyzed by thermogravimetric analyzer (TGA). Sheet-resistance was measured by 4 point probe. Surface morphology of the prepared electrode was also analyzed using scanning electron microscope (SEM) and transmission electron microscope (TEM). From our results, the synthesized copper ink showed the suitable properties to apply to inkjet printing process for the fabrication of various electronic devices.

Resume : Metals used in various industries are usually exposed to different environmental and operational conditions that can induce their corrosion. Preventing corrosion of metal is one of the biggest issues in many applications. There has been much interest in developing new materials and/or technologies to enhance the effectiveness of anti-corrosion coatings. In this study, we present a protective coating based on highly structured reduced graphene oxide (RGO)/graphene oxide (GO) onto Cu plates by spray coating and subsequent annealing process. The post-annealing treatment produces a bilayer structure of RGO/GO by partial reduction of the spray-coated GO layer. This results in excellent corrosion resistance and adhesion strength compared to GO coated Cu and RGO coated Cu plates due to the hydrophobic nature of the exposed RGO surface and the formation of Cu-O bonds with oxygen-based functional groups of GO. The process demonstrated in this study is an effective practical route for applying robust graphene coating for the protection of metal surfaces, and has potential applications in various metal products.

Resume : Carbon fiber reinforced polymer matrix composites are increasingly interested in automobile and wind energy industries. Many studies have been focused on enhancing the interfacial adhesion between the carbon fiber and the polymer matrix consisting of the composite because it is closely related to the properties and performances of resulting composite materials. Multi-walled carbon nanotubes (MWCNT) have often been used for improving the mechanical and thermal properties of polymer resins in terms of polymer nanocomposites and fiber-reinforced polymer matrix composites with assistance of dispersed MWCNT into the polymer matrix. In the present study, MWCNT nanoparticles chemically modified with polyethyleneimine dispersed in the electrolyte solution by means of an ultrasonic homogenizer were coated onto PAN-based carbon fiber surfaces and characterized. The fiber surface topography in the absence and presence of the MWCNT nanoparticles was observed by means of scanning electron microscopy. The interfacial shear strength between the MWCNT-coated carbon fiber and the thermoplastic or thermosetting polymer matrix consisting of a model fiber/polymer composite was investigated by using a single fiber microbonding testing method.

Resume : Radioactive contamination with radioactive cesium is a worldwide problem which has developed in line with the development of nuclear technology itself over the last few years. Conventional process to eliminate or clean-up polluted sites have often proved to be prohibitively expensive and labor intensive. To begin to address these shortcomings, here we examine the development and application of magnetically-responsive adsorbents that can be both directly added to and then easily retrieved after adsorption process in open environment. We demonstrated the formation of synthetic Na-birnessite-based magnetically adsorbents through electrostatic interaction and self-assembly of surface functionalized microporous shells of opposite charges onto PDDA coated magnetic nanoclusters (MNCs) to produce MNCs anchored Na-birnessite sheet nanohybrids (Birnessite/MNCs). The magnetically adsorbent showed high surface area (48.8 m2/g) with an excellent cesium adsorbent capacity and removal efficiency of 106.9 mg/g and 99.33%, respectively. Moreover, the superparamagnetism allows to effectively recover the adsorbent using an external magnetic field after the adsorption process. Results showed that the synthetic and Birnessite/MNCs model can be successfully applied to the simple and efficient technology for removal of radioactive cesium. Thus, this magnetic composite is proposed as a potential candidate material to remove radioactive cesium in open environment.

Resume : Tin phosphide (Sn4P3) has emerged as an anode for sodium ion battery (SIB) due to its high reversible capacity and low redox potential. Sn4P3 shows a synergistic Na-storage reaction to form Na15Sn4 and Na3P. Sn4P3 has also considered a promising anode material for lithium ion battery (LIB), but a very limited studies have been performed only focusing on the lithiation/delithiation reaction mechanism. Up to now, most of SIB anodes consisting of elemental P and Sn alloys are generally produced by ball milling. However, ball milling method for SnxPy is usually hard to control the morphology and produce nano scale, which leads to the deterioration of an active material resulting in capacity decay by several cycles. Therefore, hydrothermal method has received a significant attention because it can control the nanoscale morphology for the improved electrochemical performance. Herein, core-shell Sn4P3-C (carbon) composite nanospheres are fabricated by carbonization/reduction and phosphorization of SnO2-GCP (glucose-derived, carbon-rich polysaccharide) nanospheres. In particular, the size effects of nanospheres on the electrochemical performance have been investigated for SIB and LIB anode applications. The 120 nm-sized Sn4P3-C nanosphere electrode exhibits high reversible capacity, high rate capability, and ultra-long cycle stability as anodes for both SIB and LIB. Hence, the Sn4P3-C nanospheres suggest the promising anode material for the next generation SIB and LIB.

Resume : Mn3O4-based materials have received a great attention thanks to their stability, environmental compatibility and attractive performances for various end uses, such as (photo)catalysts, pseudocapacitors and gas sensors.1 In this context, the fabrication of Mn3O4 nanosystems with tailored structure/morphology by chemical vapor deposition (CVD) is of key importance in view of the target functional applications.1 The success of a CVD process is directly affected by the availability of volatile precursors with suitable characteristics. In this work, two Mn(II) complexes of formula Mn(dik)2TMEDA [TMEDA=N,N,N′,N′-tetramethylethylenediamine; dik=1,1,1,5,5,5-hexafluoro-2,4-pentanedionate (hfa) or 1,1,1-trifluoro-2,4-pentanedionate (tfa)] are proposed as molecular sources for the CVD of Mn3O4 nanosystems. The target adducts are synthesized by a simple route and characterized by a combined experimental-theoretical approach, to investigate and highlight their properties of importance for CVD utilization. The two compounds are monomeric and display high stability to air/moisture and single-step vaporization and clean fragmentation pathway, key advantages for CVD use.1 Preliminary growth experiments yielded high purity Mn3O4 nanosystems with appreciable Vis light absorption, which are very promising for eventual applications in energy production (photocatalytic H2 generation) and gas sensing of volatile organic compounds. 1 Chem. Eur. J. 2017, 23, 17954.

Resume : Ceramic nanoporous membranes are received considerable attention as an alternative to polymeric membranes for their superior thermal and chemical stability by agrressive chemicals and hot steam. Morever, their high mechanical stability enables high pressure back-flushing. They play an increasingly important role in many separation process such as the petrochemical, phamaceutical, and fine chemistry industries. The hollow fiber configuration provided by the much higher membrane packing density can make them more competitive, compared to the tubular and monolith architectures. In general, the packing densities for tubes and multi-channel monolithics are about 30-250 m2/m3 and 130-400 m2/m3, respectively. For ceramic hollow fiber membranes, packing density as high as 1000 m2/m3 can be easily obtained. Therefore, many efforts have been made in the preparation of ceramic hollow fiber membranes. The phase inversion-extrusion technique is a new method for producing ceramic hollow fiber membranes with significantly improved mechanical strength and spinning speed. A suspension of ceramic particles in solvent with a polymer binder is first prepared and then through the phase inversion-extrusion of the polymer binder via exchange with a nonsolvent. Then calcination is required to remove all the polymer binder from the membrane precursor. The ceramic hollow fiber membranes with relatively narrow pore size distribution and strong strength in this work have been successfully prepared by the phase inversion-extrusion technique. Pore size reduction occurred by control of alumina nano sol and highly uniform layers on ceramic hollow fiber membranes were observed. This work shows that the water flux of a hydrophilic membrane gives a good indication of its molecular weight cut-off (MWCO), and therefore of its separation performance in water treatment applications involving harsh environments.

Resume : Porous material with controlled mechanical and chemical properties are being developed for applications in separationsystems, sensor systems, energy transfer and storage, heterogeneous catalysts, superhydrophobic surfaces, photonic devices, drug delivery, and biomedical scaffolds. We herein reported a new method for the fabrication of anisotropic polymer scaffold contain controllable hierarchical porous structure within the scaffold structure. The scaffold are constructed via vapor depositions of poly-para-xylenes (PPXs) on sublimating template. Pore structure are formed by the gas vapor occupying the remaining vacancies lifted by sublimated water of the solid template, thus allowing the control of porosity by modulating the sublimation speed of the template. Based on manipulation of the interface properties of liquids to resolve oil-in-water emulsion system as the sublimation template, the proposed PPX scaffold is fabricated subsequently by vapor sublimation/deposition to result in structure with cavities due to the sublimated vapors or to the diffused liquids during the fabrication process. The surface morphology was first analyzed by optical microscope (OM). In addition, the three-dimensional structure was analyzed by micro-computed tomography (Micro-CT). This study introduces an innovative technology for preparing particular polymeric scaffold which can be functionally applied in different fields.

Resume : In this study, the direct hydroxylation of nanoporous low-k dielectric ( p-SiOC:H ) surface was used the appropriate of alkaline solution treatment, in order to promote the growth of self-assembled monolayer for trapped catalytic seeds to catalyze electroless plating Co-alloyed layer. The hydroxylation of p-SiOC:H properties were evaluated by water contact angle, dielectric properties analysis, ATR-FTIR analysis. The water contact angle of p-SiOC:H film has rapidly decreased from ~75 to ~35 degrees which the methyl groups have replaced with a hydroxyl or substituted hydroxyl groups after alkaline solution modification within 30 sec. The water contact angle reached the saturation value (~25 degree) after 60 sec treated. The influences of the hydroxyl treatment on dielectric properties were characterized by I-V and C-V measurement. The leakage currents and dielectric constants of p-SiOC:H film can be maintained by an appropriate hydroxyl treatment time. In other words, inappropriate hydroxyl treatment time will induced a rapid leakage current and dielectric constant increase for p-SiOC:H films. ATR-FTIR analysis identified hydrophobic Si-CH3 groups not only removed but also formed hydrophilic -OH groups on p-SiOC:H surface by alkaline solution immersion. Uniform methyl–derived self-assembled monolayer has grown on hydroxylated p-SiOC:H dielectric surface into a solution containing a mixture of the octadecyltrichlorosilane (OTS) and toluene. In order to trap catalytic seeds (metal catalyst formation), OTS-SAMs were using a dual surface modification to enhance metal ions absorbed, then catalytic particles were formed in reducing agent solution. The SEM images reveal that electroless Co-alloyed layer grown on the seed-trapping layer by methyl–derived self-assembled monolayers of p-SiOC:H dielectric film.

Resume : The reduction of radar backscatter with the use of radar-absorbing material has important implications in the stealth technology and electromagnetic compatibility. Nanocomposites consisting of carbon nanotubes (CNTs) and magnetic materials have potential applications in various fields like magnetoresistive random access memory, spin-polarized transportation, Electromagnetic interference shielding (EMI) and radar absorption. Metal-incorporated CNTs are found to be good microwave absorbers due to the modification of their electronic structure which helps in dielectric and magnetic loss of the incoming electromagnetic wave. In this work, we have synthesized the metal filled MWCNT with efficient and simple one pot chemical vapor deposition techniques using pyrolysis of metal precursor. CNTs filled with the 3d transition metals like Fe, Co. Ni, Mn renders them good electromagnetic-interference shielding and microwave absorbers behavior. The microwave absorption properties of these hybrids metal filled CNTs in the PVDF polymer matrix are studied in X band (8-12 GHz frequency range). The synergistic microwave absorption due to the enhanced interfacial electric polarization and ferromagnetic resonance of magnetic nanoparticles leads to enhanced microwave absorption and EMI shielding. The role of magnetism and its effect on the EMI shielding and radar absorption will be discussed. These hybrid composite systems have great potential for commercial and military applications.

Resume : In our work we describe process of electrochemical exfoliation of graphene sheet stacks, creating defective multilayer structures. Their chemical properties can be adjusted during synthesis, by control of electrolyte and potential/current. Reduction and sonication of our powder, allows to produce large volume of cheap GSS material with low resistivity (0.3 to 10 ohm) and good applications for electrodes, either in energy storage or energy production, or sensors. Surface chemistry allows applications in electrolysis which is further studied. Characterization of material and simple electrodes is presented. Acknowledgement: Authors greatly acknowledge CO2EXIDE, H2020 project for financial support.

Resume : This study present novel synthetic process for inorganic-organic (I-O) nanohybrids using alkoxysilane-functionalized amphiphilic polymer (AFAP) precursors having various molecular weight and hydrophilic/hydrophobic balance. Through a conventional hydrolytic polycondensation process, I-O nanohyrbids dispersed at various solvents could be obtained. Obtained I-O nanohybrid solutions were stable for several months and could be coated on various substrates which could be thermally cured at relatively low temperature within 10 minutes. I-O nanohybrid solutions could form transparent coating layer onto glass and PET films without any crack. Nanohybrid coated PET films had flexibility and high transparency. Fig. 1 shows SEM images of coating film formed by thermal curing of I-O nanohybrid materials prepared using AFAP precursor. Images showed that 10 nm-sized in inorganic nanoparticles were formed and homogenously dispersed at whole coating layer. Obtained I-O hybrid films showed high surface hardness with high transparency, which could be used as hard coating materials for plastic films and anti-corrosive coating for various metals.

Resume : Polyimides (PIs) have been widely used in various industrial fields, such as automobiles, microelectronics, displays, and aerospace, because of their excellent thermal stability, chemical resistance, and electrical and mechanical properties. These days, with the rapid development of miniaturized and highly efficient electrical/electronic devices, suitable technologies for the coating of a thin yet thermally and electrically insulating layer on fine-structured metal substrates has become increasingly important. In this study, we aim to fabricate a uniform and conformal PI film on various shapes of metal substrates. Polyamic acid (PAA) colloids were synthesized, which were electrophoretically deposited and thermally imidized, resulting in PI coatings on metal substrates. We demonstrate the counterions play an important role both in the formation of a stable PAA colloid, which is necessary to obtain a uniform film during EPD, and in increasing the imidization rate. Mechanism of this phenomenon is discussed based on various characterizations using DLS, TEM, zeta-potential meter, FT-IR, NMR, etc. Uniform and conformal PI coating was obtained on fine-structured substrates such as flat coil and micro-mesh. PI/silica nanohybrid coatings were obtained by EPD of PAA/silica nanohybrid colloids. Sol-gel method was employed for synthesis and surface modification of silica nanoparticles. PAA/silica nanohybrid colloids could be successfully prepared by in-situ polymerization of PAA in the presence of surface-modified silica nanoparticles. These PI/silica nanohybrid coatings exhibited enhanced performance in electrical insulation compared to PI coatings. Especially, the corona-resistance was dramatically improved by ~ 5 times. EPD technology has another strong merit regarding environmental issue. The amount of toxic solvents used for preparing PAA resin can be much reduced. Based on our results, more advanced application of PI coating is expected to various industrial areas.

Resume : Resistive switching (RS) has become a hot topic for its potential application in new generation non-volatile memories, such as resistive random access memories (ReRAMs), as well as for neuromorphic computing. RS, i.e. the change in resistance of a heterostructure (an active material sandwiched between 2 electrodes) under the effect of an applied electric field, has been reported for several manganite systems [1, 2]. In this work, LaMnO3±δ (LMO) grown as thin films by Pulsed Injection Metal Organic Chemical Vapour Deposition (PI)-MOCVD was chosen as active material for RS. The MOCVD deposition was optimized to obtain highly dense films suitable for their integration in a ReRAM heterostructure. To study the effect of the films texture LMO was grown on different substrates, enabling the comparison of epitaxial (on LaAlO3) and polycrystalline films (on Si3N4/SiO2/Si and on platinized Si). In addition, the combination of XRD and Raman showed that the crystalline phase (orthorhombic and/or rhombohedral) of the films can be tuned by changing the deposition conditions (temperature, thickness, etc). Thus, through a set of optimized samples, the influence of structural properties (phase, texture) of dense LMO films on the electrical conductivity of LMO has been studied. Furthermore, the RS properties of the optimized heterostructures (active material and electrodes) will also be presented. [1] R. Waser, R. Dittmann, C. Staikov, and K. Szot, “Redox-based resistive switching memories nanoionic mechanisms, prospects, and challenges,” Advanced Materials, vol. 21, no. 25–26. pp. 2632–2663, 2009. [2] A. Sawa, “Resistive switching in transition metal oxides,” Materials Today, vol. 11, no. 6. pp. 28–36, 2008.

Resume : Over the past few decades considerable attention has been devoted to metal-oxide semiconductors, which have found extremely important applications in various fields. Among different metal-oxide semiconductors, molybdenum trioxide (MoO3) has attracted interest because of its multifaced functional properties. It has applications in many devices, such as: photocatalytic reactors, sensors, photochromic devices, supercapacitors, batteries or photovoltaic cells. A variety of techniques have been developed to control the morphologies of MoO3, for example the solvent thermal process, the electrochemical method and the template based approach . In this work, we report a novel method for preparing transparent MoO3 film via anodization of thin Mo films already deposited at room temperature onto the FTO substrate using a magnetron sputtering system. The morphology of obtained materials was characterized by SEM and their properties were examined using spectroscopic techniques (UV-Vis, Raman, XPS, photoluminescence spectroscopies) and electrochemical methods (impedance spectroscopy, cyclic voltammetry). Formed MoO3 layers allow for transmission of visible light which is crucial for application in semi-transparent solar or electrochromic cells. MS acknowledges the National Science Centre of Poland, NCN, for financial support under contract no 2016/23/N/ST5/02071.

Resume : The electrochemical splitting of water provides an elegant way to store renewable energy, but is limited by the cost of the noble metals used as catalysts. Among the catalysts used for the reduction of water to dihydrogen, layered MoS2 has been identified as one of the most promising materials as it can be engineered to provide not only a large surface area but also abundance of unsaturated and reactive coordination sites. Using Mo(NMe2)4 and H2S as precursors, we are able to deposit a layer of MoS2 on substrates at low temperature. We use QCM analysis during the ALD deposition process to monitor the reaction and identify 95 °C as the optimal reactor temperature. The identity and structure of the film are confirmed by spectroscopic ellipsometry, X-ray reflectometry, and X-ray photoelectron spectroscopy. The electrochemical performance of MoS2 thin films on planar and nanostructured “anodic” sample is quantified and compared. The current densities can be maximized based on the geometry of the “anodic” nanoporous substrates.

Resume : The neverending demand for energy and exploitation of its natural resources are the reason for searching new functional materials that can be used for energy harvesting from attainable sources. In the extensive group of such materials, TiO2 nanotubes (NTs) evoke much interest not only because of their ability to convert sun energy into electricity but also due to their usage in solar driven processes such as catalysis or water splitting. In this work, it is shown that Cu decoration of TiO2NTs leads to improved electrochemical, optical and photoelectrochemical properties in the visible light region. 2 µm-long TiO2NTs have been prepared in anodization process followed by calcination in order to ensure the amorphous-anatase phase transformation. Next, thin copper layers (up to 50 nm) have been sputtered and subsequently dewetted using UV laser illumination at 266 or 355 nm (up to 50 pulses). The presence of Cu nanoparticles in the crown position on NTs edges was confirmed by SEM imaging and the XPS inspection revealed presence of both metallic and oxidized states (CuO) of copper. It was observed that metal decorated NT structures generate much higher photocurrents in comparison to bare TiO2NTs and the registered signal is stable for at least 15 minutes. Photoelectrochemical performance of the prepared material indicates potential for application in solar driven processes. This work is financed via grant no 2012/07/D/ST5/02269.

Resume : Composite materials, consisting of an organic electron donor and an inorganic oxide semiconductor electron acceptor, have attracted much attention in the past decades. Such composites exhibit novel properties derived from the successful combination of the characteristics of parent constituents. Most possible applications of such composites require electrode polarization. According, materials under applied voltage may change their structure, band bending and in consequence electronic properties are modulated. Such control of the electrode potential has a large influence on its optical, electrochemical and photoelectrochemical properties. In this work we show the impact of applied potential on photoelectrochemical properties of a composite material containing hydrogenated titania nanotubes and poly(3,4-ethylenedioxythiophene) with iron hexacyanoferrate (H-TiO2/pEDOT:Fehcf) acting as a redox centre. The uniform infiltration and direct contact between the organic part and the metal oxide support was inspected by transmission electron microscopy (TEM) together with energy dispersive X-ray spectroscopy (EDX). We present that by changing the potential of the electrode, we could modulate the photoactivity of the whole heterojunction affected by processes occurring at the electrode/electrolyte interface. KS acknowledge the National Science Centre of Poland, NCN, for financial support under contract no 2012/07/D/ST5/02269.

Resume : Polymer electrolyte membrane fuel cell (PEMFC) is ideal for next-generation energy conversion device due to its environmental friendly products and high energy conversion efficiency. Among the PEMFC catalyst support materials, carbon-based supports are widely used as a catalyst support for commercialized PEMFC because of its high surface area and electrical conductivity. However, the carbon-based catalyst support has problem. That is the reduction of catalytic activity due to corrosion of carbon support, leading to the sintering of Pt catalyst and generation of CO, CO2. Therefore, inorganic material is necessary to solve this problem. Among inorganic materials, titanium oxide is spotlighted as a substitute for carbon support because it has high durability in acidic atmosphere and PEMFC operation conditions. However, the carbon-based support is still advantageous as an electrode support for the PEMFC due to the low electrical conductivity of the titanium oxide. In this study, we focused on the improvement of electrical conductivity through nitrogen doping, resulting in the durability enhancement under the acidic atmosphere. N-doped TiO2 support was synthesized with TiO2 and urea for nitrogen source by annealing under 4% H2/Ar atmosphere. The physicochemical characteristics were analyzed by XRD, FE-TEM, XPS and ICP-MS. Electrochemical property of N-doped TiO2 for oxygen reduction reaction (ORR) was investigated under O2 saturated 0.5M H2SO4 in potential window of 0.0 ~ 1.4 V (vs. NHE) with linear sweep voltammetry (LSV). The electrochemical surface area (ECSA) was identified by cyclic voltammetry (CV) under N2 saturated 0.5M H2SO4 in potential window of 0.0 ~ 1.4 V (vs. NHE). Both experiments were measured by long-term cycle (10000cycles) test under accelerated durability test (ADT) method. Through the measurement of membrane-electrode assembly(MEA) performance (I-V curve), Pt/N-doped TiO¬2 catalyst exhibited high durability and enhanced catalytic activity compared with Pt/TiO2¬. under PEMFC ADT operation condition.

Resume : CuO/Cu2O composites were formed by anodization of bulk copper foil and thin copper film deposited on top of the nanostructured silicon. Anodization was carried out in aqueous solution of sodium hydroxide for 30 min in galvanostatic mode at current density of 1.5 – 7 mA/cm2. According to Raman spectroscopy fabricated samples contain both copper oxide (II) and copper oxide (I) and can be considered as composites. It was found that reflectance of the samples varied from 10 to 45 % in the 200 – 700 nm spectral range. A photoluminescence (PL) spectra allowed to determine that optical band gap of obtained Cu2O is equal to 2.1 eV – the value of band gap of bulk Cu2O. Observed peaks on PL spectra related to direct band-to-band recombination of charge carriers allowed to suggest that CuO/Cu2O samples have low concentration of crystal lattice defects and high crystallinity. The voltammograms scanned using three-electrode electrochemical cell showed that electric current in the samples increase under illumination in comparison with current density in the dark. Remarkable that no observable difference between CuO/Cu2O on copper foil and CuO/Cu2O on nanostructured silicon was found. The obtained results allow us to conclude that the developed method of CuO/Cu2O preparation is promising for producing photoanodes, which can be applied in photoelectrochemical cells for solar water splitting.

Resume : Over the past decades, extensive effort has been made and successes have been achieved to create topological surface patterns, and the ideas to induce topographically derived responses in both in vivo and in vitro biological systems have become essential. We herein report a new approach for the creation of displaceable and switchable surface pattern structures by using a vapor deposited, functionalized poly-p-xylene coating. The coating comprises an integrated disulfide moiety within the functional group. The reversibly interface platform is achieved through the redox thiol-disulfide interchange reaction, and different programmable properties can be introduced on the surface by altering the immobilized functional molecules. Such modified interface provides chemically- and topologically-defined signals for the recognition of cell adhesion/resistance and/or hydrophilic/hydrophobic surfaces in registered locations. More importantly, the alternating these topographically-defined properties/biological responses are achievable by the coating technology in real time from an interacting cell-adherent state to a non-interactive cell-repellent state, or vice versa, and the switching between these dynamic properties is reversible for a number of cycles. The confinement of these conjugation reactions at selected areas is enabled by using microcontact printing (μCP). The reported coating technology provides a dynamically programmable design criterion for biointerface.

Resume : Crystalline titanium-dioxide is a widely used photocatalyst, but amorphous TiO2 is considered not to have photocatalytic activity. Recently it has been found that amorphous TiO2 deposited by atomic layer deposition (ALD) might have photocatalytic activity. During our work we studied the properties of ALD grown amorphous and crystalline TiO2, and as a reference we examined ALD Al2O3 and ZnO. The oxide layers were deposited on SiO2 and PMMA (poly(methyl-methacrylate)) nanoparticles, PVA (poly(vinylalcohol)) and PVP (poly(vinylpyrrolidone)) nanofibers. The bare and core/shell composite nanoparticles and nanofibers were investigated by SEM-EDX, TEM, FT-IR and XRD. Finally, the photocatalytic activities were studied. The photocatalytic reactions were investigated by the decomposition of aqueous methylene orange, monitored by UV-Vis. The TiO2 prepared at 50 and 80 °C was amorphous, while at 300 °C it was crytalline, the Al2O3 was amorphous at 50 °C, 80 °C and 250 °C and the ZnO was crystalline at all temperatures. The amorphous TiO2 deposited on the SiO2 and PMMA nanoparticles indeed had some photocatalytic effect, the Al2O3 was not active, while the ZnO showed good photocatalytic activity. The phototcatalytic performance was greatly influenced by the type of the support material.

Resume : In recent times, the rapid development of communication technology has posed serious threat of electromagnetic interference (EMI), affecting not only function of electronic devices but also harming human health. Consequently, in search of a material that can shield against harmful microwave (MW) radiation, we have developed the nanographite-nano iron-polymethylmethacrylate (NG-nFe-PMMA) nanocomposite through melt blending technique. In the present work, nanoscale iron (nFe) particles were prepared through chemical reduction of ferric chloride by sodium borohydride. Further, Le Bail refinement of XRD patterns of nFe particles confirm the formation of desired body-centred cubic phase. Scanning and transmission electron microscopy confirms the homogeneous dispersion of NG and nFe particles in PMMA matrix. The complex permittivity and permeability spectra, in 2-18 GHz frequency range, were measured using vector network analyser (VNA). The minimum reflection loss, calculated from transmission line theory using Naito-Suetake model, of -35.8 dB (99.97% MW absorption) was attained in NG(2.0 wt%)-Fe(30.0 wt%)-PMMA nanocomposite sample at 13.2 GHz MW frequency with 1.9 mm thickness. Furthermore, the prepared nanocomposite sample shows broadband absorption, over X- to Ku-band, for the reflection loss of -10 dB (90% MW absorption) or less. The MW absorption data indicates that the prepared nanocomposite samples can be used in potential light weight commercial MW absorbing applications.

Resume : Many modern lead-free piezoelectric materials are compounds of expensive and rare elements. We are instead working towards piezoelectrics based on α-quartz (SiO2) synthesized in thin film form from the crystallization at high temperature of amorphous ALD-grown silica films on Si(100). The silicon substrate has a role in selecting α-quartz and avoiding the other polymorphs of silica. It is further required that the devitrification temperature of the film be sufficiently low, which we attempt to ensure by introducing a layer of Sr-based melting agent within the heterostructure via PLD. Success in this effort will allow modifying the films’ piezoelectric performance with dopants such as GeO2, which can be incorporated in the film during the ALD growth.

Resume : To date, the most common exploited method for the metallization of polymers is the electrochemical procedure which generally produces highly toxic residues such as the carcinogenic hexavalent chromium (Cr6+) and the trivalent chromium (Cr3+). Following European directives a recently and environment friendly new method for the production of metallic looking films on polymeric substrates has been proposed. Such method employs a chromium target in a physical vapour deposition chamber (PVD) in a constant nitrogen flow to produce CrNx coatings. In addition, depending on the type of substrates, the plasma enhanced chemical vapour deposition (PECVD) technique may also be applied prior to the PVD in order to activate the polymeric surface and thus increasing the coating’s adhesion. In this work, we present adhesion evaluation results for a set of CrNx coatings deposited on polyamide (PA), polypropylene (PP) and acrylonitrile butadiene styrene (ABS) substrates, using the newly improved and combined PVD/PECVD technique. The samples were then characterized by their surface roughness before and after the CrNx deposition by profilometry . Quantitative evaluation of the adhesion was done by measuring the maximum force used to remove the metallic coating from the substrate, using the “pull-off” technique. The results have shown improved adhesion strength for the coatings deposited on PA and ABS polymers when compared to PP substrates.

Resume : Biosensors generally comprise biomolecules bound to large surface area transducers that convert the biological interaction into a measurable signal. As transducers, nanoporous ZnO thin films have been demonstrated optimal for cutting-edge biosensing devices, due to the combination of well-suited physicochemical properties with the possible nano-confinement of biomolecules. In this contribution, synthesis of nanoporous ZnO thin films is demonstrated through annealing of carbon-containing ZnO (zincone-like) layers obtained by plasma enhanced-atomic layer deposition (PE-ALD) with possible application in biosensing. The zincone-like layers are deposited through sub-saturated PE-ALD adopting diethylzinc, and O2 plasma with time steps below self-limiting values. Nanoporous ZnO thin films were obtained by annealing the zincone-like layers between 100-600 °C. The removal of carbon-impurities, development of controlled nanoporosity, and formation and growth of ZnO crystallites were followed in-situ during annealing by spectroscopic ellipsometry and X-ray diffraction (XRD). The layers were found to develop nanoporosity tuneable in the range 1-5%, with pore size between 0.27-2 nm as measured with ellipsometric porosimetry, as a function of the plasma time step and post-annealing temperature. Furthermore, the crystallinity and crystallite orientation could be controlled, ranging from powder-like to (100) preferential texture, as measured by synchrotron-light grazing incidence XRD.

Resume : To achieve reasonable stability without compromising the activity of electrodes for energy storage and water splitting, rational design of three-dimensional nanostructured material is required. Herein, we successfully prepare the 3D (Ni,Co)Se2 with nanocactus-like structure as the support to scaffold the nonconductive layered double hydroxide (LDHs) and to serve as a self-standing current collector itself. Firstly, the special cactus-like architecture can integrate the advantages of a 1D structure that can form an efficient pathway for charge transport, with those of a 2D structure that exhibits mechanical stability and strength. Secondly, transition metal chalcogenides (Ni,Co)Se2 can possess abundant active sites, desirable electrical conductivity, and robust structure, which are considered as the ideal candidates for supporting materials. Furthermore, when layered double hydroxide (LDHs), such as NiCo LDH and NiFe LDH, are assembled on the (Ni,Co)Se2 support, these open 3D nanostructures can dramatically increase the interfacial area between the electrode and the electrolyte to provide more active sites, and facilitate transport of the reaction product. In this project, NiCo LDH and NiFe LDH are assembled on the supporting (Ni,Co)Se2, denoted as (Ni,Co)Se2/NiCo LDH and (Ni,Co)Se2/NiFe LDH, for the application of supercapacitor and water splitting, respectively. As the result, (Ni,Co)Se2/NiCo LDH can achieve the high capacitance of ≈1225 F g-1 at the current density of 1 A g-1. In addition, the nanocomposite possesses ≈76% capacitance when the current density increases to the 15 A g-1, and possesses ≈90% capacitance retention even after 3000 cycles. As for the OER performance, the (Ni,Co)Se2/NiFe LDH exhibites an excellent OER activity in 1.0 M KOH with a small overpotential of ≈170 mV at the current density of 10 mA cm−2 and a low Tafel slope of ≈69 mV dec−1 and keeps high stability during a 30 h measurement. Based on the excellent performance, especially the great activity and excellent stability, it can be seen that our 3D (Ni,Co)Se2 support and selenide/LDHs nano-combination present a great potential for both energy conversion and storage applications.

Resume : TiO2 and ZnO are widely researched photocatalysts because of their chemical stability, non-toxicity, and high reactivity. However, the fast recombination of the photo-excited charge carriers leads to their short lifetime, so it is desirable to use a co-catalyst to improve the electro-hole separation. Carbon nanomaterials are attractive co-catalysts, due to their high surface area and stability. These nanomaterials include carbon aerogels, which possess porous structure and diverse morphologies. Introducing nitrogen into the carbon aerogel can significantly alter the electron distribution of the carbon matrix even at low concentrations. Metal oxides can be deposited on the nitrogen doped carbon aerogel carriers with several techniques, such as atomic layer deposition, which allows the coating of surface of nanostructures in a homogeneous way. In this work, a nitrogen containing carbon aerogel was prepared from a resorcinol-melamine-formaldehyde polymer gel precursor. The polymer gel was supercritically dried with CO2, and the carbonization of the resulting polymer aerogel yielded the carbon aerogel. Atomic layer deposition was utilized to coat the polymer and carbon aerogels with TiO2 and ZnO layers. The aerogels and the metal oxide/aerogel composites were characterized with TG/DTA-MS, FTIR and Raman spectroscopy, XRD and SEM-EDX techniques, and their photocatalytic activity was investigated.

Resume : Different from chemical vapour deposition (CVD) and physical vapour deposition (PVD), atomic layer deposition (ALD) is based on saturated surface reactions. In this case, the thin films are grown in a layer-by-layer fashion allowing sub-nanometer thickness control, low temperature depositions, good uniformity and superior step coverage on high specific surface area components compared to CVD and PVD. These advantages of ALD over other thin film deposition processes have been conventionally applied mainly in semiconductor electronic industry on the preparation of layers of outstanding High-K dielectric materials. But, due to the advances in tool design and recipe development, the importance of ALD is rapidly expanding for producing innovative nanoscale materials. ALD new applications are highly multidisciplinar. It has an emerging potential on photo-voltaic cells, flexible electronics, enhanced performance glass, paper and textiles, new generation transistors, sensors, and advanced energy materials technology. Innovations brought by nanotechnology to biosciences and biosensors are also proving to be good candidates to benefit from these potentialities and its surface functionalization possibilities. Some of these advanced applications require the deposition of hybrid materials that could combine the beneficial aspects of both inorganic and organic phases. Molecular layer deposition (MLD) methods extend the ALD strategy to include organic and hybrid organic?inorganic polymeric materials, so a combination of both techniques opens the door to the creating of highly at-tractive nanostructural frameworks.

Resume : As the paradigm shift of energy system from petroleum to electricity by the view point of sustainability, development of high performance electric devices becomes more and more important. Insulating materials are one of the key technologies for their practical application because the electric devices will be driven at higher voltage for their performance, and because the electric devices of next generation with complex shape cannot be coated by the today’s coating techniques. Therefore, the development of those materials with thermostability and electrodeposition ability is quite important for the production of high performance electric devices of the next generation. We have developed various thermostable electrodeposition coating materials from soluble polyimides. Anionic electro deposition coating was successfully performed by the poly(amic acid) nano particles, which can be converted to polyimides after thermal annealing. Hybrid coating of polyimide/hydrotalcite was also performed. Cationic electrodeposition materials have prepared by the polyimide nano particles with dimethylamino groups as substituents, which can deposit on copper substrates and make coating layer with thermostablity more than 270 C.

Resume : Multifunctional nanostructures are appealing materials since they combine on a single nano-object different physical and/or chemical properties. Concretely, nanostructured hybrids comprising a magnetic component can be potentially applied in both day to day and high tech applications such as magnetic recording, biotechnology (biosensors, hyperthermia) and catalysis (recoverable catalysts, nanoheaters). In this work we have used, hard-ferromagnetic Co-based nanorods (NRs) as seeds to grow on them Au, Pt and Ni. Depending on the metal grown on Co, we can modulate the already existing properties, or add new properties not present in the initial Co seed. Thus, the same initial nano-objects can be transformed at will in order to satisfy completely different specifications associated to different applications. For instance, a mixed shell of Sn, Pt (or Ni) and Au deposited on Co nanorods, prevents Co NRs from oxidation allowing using the Co nanorods in aqueous environment.1 In parallel, Co-Au NRs with a continuous and thick Au shell have been, theoretically, demonstrated as excellent candidates to overcome the nanomolar range detection limit for biosensing applications.2 The interaction of Co with another magnetic metal modifies the hard magnetic character of pure Co nanorods in order to obtain hybrids that can act as magnetically activated nanoheaters and/or nanocatalysts. In this respect, Co-Ni NRs are envisaged to act as nanoheaters in the high temperature catalytic Fischer Tropsch synthesis thanks to the high specific absorption rate values expected as a result of the interaction between the two magnetic metals due to the soft character of Ni and the high Curie temperature of the Co.3 Moreover, Co-Ni NRs may even catalyze the methane reforming process where Ni is known to be an excellent catalyst.4 We have developed a synthesis strategy in order to either fully cover the Co NR surface with the second material or mostly only the tips. The growth of a homogeneous shell has been achieved by using an organometallic Sn precursor which it is inferred to reduce the interfacial energy between the two phases.1 1Lentijo-Mozo, S. et al. ACS Nano, 2015, 9, 2792. 2Schrittwieser, S. et al. ACS Nano, 2012, 6, 791. 3Meffre, A. et al. Nano Lett. 2015, 15, 3241. 4Zhao, Z. et al. RSC Adv. 2016, 6, 49487.

Resume : The development of nanostructured thin layers is a great interest for a wide range of application fields (optics, plasmonics, catalysis, sensors, …). In the domain of photo-catalysis, titanium dioxide is widely used for its excellent properties. This work was focused on the fabrication and the characterization of inverse opal structures that could be used as a catalyst thanks to their large specific surfaces. TiO2 thin films were obtained by Atomic Layer Deposition on polystyrene nanobeads orderly organized on silicon substrates. ALD process allows the growth of dense and conformal layers with a perfect control of the thickness. The deposited layers can even cover holes and cavities unlike classical CVD. An inverse opal structure of titanium dioxide is obtained by burning the polystyrene beads with a post-annealing process. The aim of this work was to optimize the conditions for the fabrication of inverse opals of TiO2 (temperature, pressure, precursor injection times, …) and to characterize the morphology, structure and properties of these deposits (SEM, TEM, XPS, Raman spectroscopy). First results showed the growth of amorphous TiO2 layers before the annealing process. Then, after annealing, titanium dioxide was mainly crystallised in the anatase phase. A very low amount of carbon was detected in the films, due to polystyrene combustion residues. A rough and hemispherical structure was observed by electron microscopies.

Resume : Surface enhanced raman spectroscopy（SERS）is a powerful analytical technique that reveals structural information of molecules to provide fast screening and detection applications. In this research, sensitive SERS substrates with hotspots on a large scale from massive nanogaps can be fabricated by assembling polyhedral gold nanoparticles on the massed Ag mirror via 1,2-ethanedithiol monolayer as ultra-thin spacer. Preparation of different diameter of nanoparticles with excellent morphology control is necessary for demonstrations of their shape- dependent optical properties. Theoretically, SERS activity is related to the large localized field enhancement such as the presence of sharp tips and is thus critically shape-dependent for nanoparticles. With different morphologies of gold nanoparticles, we can not only confirm our substrate is more stable than traditional silver nanoparticles coated substrate but also make a denser close packed structure with sharp corners. Furthermore, we have proved that self-assembly structure combine with nanoparticle on mirror(NPOM) configuration can increase SERS signal dramatically. In our work, we applied seed-mediated synthesis method for the preparation of gold nanoparticles[1]. It's the first synthesis process done in aqueous solution. The combination of using cetyltrimethylammonium chloride (CTAC) surfactant and a small amount of NaBr to control the bromide concentration in the growth solution was important to the formation of nanoparticles. Variation in the volume of ascorbic acid added to the growth solution enabled the fine control of nanocrystal morphology. Next, by spin coating we can fabricate a close packed gold nanoparticles monolayer on a dielectric layer that deposited on silver mirror. Due to the existence of ultra-thin dielectric spacer, it can prevent the directly touch of two metallic surfaces, which prevails the strong plasmonic interaction at the nanogap between two metal surfaces. By this design, we were able to conclude size and shape effect of noble metal nanoparticles on SERS.

Resume : The effects of deposition temperatures (70-300 ̊C) on electrical properties of surface-modified iron oxide nanoparticles sitting on SiO2-coated Si substrate were investigated representing the metal-oxide-semiconductor characteristics. The surface root-mean-square roughness of the deposited nanoparticles increased when deposition temperature was increased at 150 ̊C but declined when the heating temperature was intensified at 200 and 300 ̊C. This is caused by eradication of hydrophobic interaction between the surface-modified nanoparticles proportional with deposition temperature. Sample deposited at 70 ̊C showed the highest breakdown field at 1.47 x 10^-3 MV/cm.

Resume : Powders are used in a large number of different fields like medical, chemical, ceramics, and cosmetics industries. A tendency nowadays is the surface functionalization of powders in order to have, for example, a moisture barrier, a catalysis property, a different colour or another specific chemical property. This powder surface functionalization can be performed by coating. Atomic Layer Deposition technology is a promising solution as it is a self-limited surface reaction, and as, under vacuum, gaseous precursors are in contact with all powder surface. Atomic Layer Deposition enable conformal and uniform layer coatings on powders. In this presentation, Microtest will explain several different applications of powder coating by Atomic Layer Deposition. Technical solutions for powder coating in ALD reactor will also be shown.

Resume : Atomic layer deposition (ALD) is known to be an excellent technique for the deposition of thin films with uniform thickness over micro- and nanoscale 3D structures. The superior conformality of ALD is a direct consequence of the self-saturated surface reaction control and makes the technique increasingly useful in a variety of applications including catalysis and energy conversion and storage. In this work, we present an extensive study on the conformality of ALD in nanoporous materials [1-3]. Porous silica and titania thin films with pore sizes in the low mesoporous regime (< 10 nm) were considered in order to get insights on the minimum pore diameter that can be achieved by ALD. Novel in situ characterization techniques were developed to monitor the pore filling by ALD. Synchrotron-based x-ray fluorescence and scattering techniques provided cycle-per-cycle information on the material uptake and densification of the porous film, while ellipsometric porosimetry was used to quantify the pore size reduction. This study nicely demonstrated the ability of ALD to tune the diameter of nanopores down to the molecular level. In addition, examples will be shown where ALD in mesoporous materials successfully resulted in tailored catalysts. [1] J. Dendooven et al., Langmuir 28, 3852, 2012. [2] J. Dendooven et al., Chem. Mater. 24, 1992, 2012. [3] J. Dendooven et al., Nanoscale 6, 14991, 2014.

Resume : Tuning the Metal-Insulator transition (MIT) of nikelate perovskites, RENiO3, where RE refers to a rare-earth, is possible by changing the Rare-earth cation of the structure [1,2]. Alternatively, this transition can also be shifted by other mechanisms, for instance, inducing structural distortions via epitaxial strain [3]. However, it still remains unclear how the ReNiO3 films accommodate when they are epitaxially grown onto different substrates. Here, we use the aberration corrected Scanning transmission Electron Microscope (STEM) to precisely characterize the atomic structure of tensile and compressive strained LaNiO3 (LNO) and NdNiO3 (NNO) thin films grown by chemical solution deposition (CSD) processes. Firstly, we discuss the influence of the selected substrate on the final defect landscape, which is different in each case. Secondly, we elucidate a fundamental link between strain and the commonest defect observed in nikelate films, the Ruddlesden-Popper fault (RPF), which will ultimately impinge on the electrical properties of the films. Finally, we identify the exact position of each atomic column by applying a center of mass refinement routine, enabling us to locally quantify, with subatomic resolution, any atomic-atomic spacing or displacement. The obtained results unveil additional distortions appearing on either side of the RPFs, revealing an unforeseen polar-like distortion regarding the Ni atoms. [1] L. Medarde, J. Phys. Condens. Matter 9, 1679 (1997). [2] G. Catalan, Phase Transitions 81, 729 (2008). [3] S. Catalano, M. Gibert, V. Bisogni, F. He, R. Sutarto, M. Viret, P. Zubko, R. Scherwitzl, G. A. Sawatzky, and J. Triscone, 62506, (2015). Authors acknowledge the MICIN (NANOSELECT, CSD2007-00041 and MAT2014-51778-C2-1-R), Severo Ochoa SEV-2015-0496 grant, the RyC-2012–11709 contract of J.G. and the Generalitat de Catalunya (2014SGR 753 and Xarmae) project. The STEM microscopy work was conducted in the ICTS-CNME at UCM as well as at the Laboratorio de Microscopias Avanzadas (LMA) at Instituto de Nanociencia de Aragon (INA) at the University of Zaragoza. Authors acknowledge the ICTS-CNME for offering access to their instruments and expertise. Electron microscopy

Resume : Zirconium is used as a getter, for hydrogen storage or in corrosion resistant alloys in nuclear reactors where a failure mechanism was found directly related to the presence of H. To develop new protective coatings of claddings, the knowledge of the Zr H interaction is the crucial step for theory, data interpretation and technology. Atomically resolved STM (Scanning Tunnelling Microscopy), PES (Photoelectron Spectroscopy) and PED (Photoelectron Diffraction) were applied to study a surface of the Zr(0001) single crystal and its interaction with H. In our work, the Zr surface was cleaned with several cycles of ion bombardment and annealing up to 750°C in UHV conditions. LEED (Low Energy Electron Diffraction) shows simple (1×1) patterns and the Zr 3d peak at 179.1 eV exhibits a shoulder shifted by 0.3 eV to higher BE (Binding Energy). STM images display a high density of steps at terraces. PED shows trigonal symmetry of the clean Zr surface where the experimental data agrees with simulations. We studied effect of the Zr surface exposition to H2 gas by monitoring of the Zr 3d peak. Typically, two new peaks were identified at positions shifted by: 0.6eV and 1.4 eV to higher BE. We suggest that the 1.4 eV shift is due to Zr H bond. With increasing time, the H from Zr H dissolves in the bulk (intensity decrease at 1.4 eV) forming a solid solution that is reflected by increased intensity of the 0.6 eV shifted peak. We found that the hydrogen content of this probed region is strongly influenced by adsorption of a small amount of Si (0.5 ML) that erases any signal connected with H.

Resume : The widespread utilization of renewable energy will require energy dense and cost-effective methods for storage. This challenge could be met by coupling renewable electricity to the reduction of carbon dioxide and/or protons to fuels and the oxidation of water to O2, providing, in net, a viable scheme for artificial photosynthesis. Likewise, the resulting fuels could be recombined in a fuel cell to comprise a net carbon-neutral cycle for energy storage and recovery. All electrochemical energy conversion devices operate by carrying out anodic and cathodic half reactions at spatially separated electrodes. Crossover of products and/or reactants from one electrode to the other leads, typically, to parasitic short circuits which reduce the efficiency of energy storage and release. We have used layer-by-layer deposition methods to develop a class of anode and cathode materials that are resistant to parasitic cross-over reactions, thereby enabling the assembly of membrane-free fuel cells and electrolyzers. Our latest efforts toward developing high selective anode and cathode materials will be discussed.

Resume : The storage of renewable energy via the splitting of water into the elements is limited by the low efficiency and high cost of bifunctional positive electrodes. The best bifunctional electrocatalyst for water oxidation and dioxygen reduction is a mixture of platinum and iridium. Here, we focus on the fabrication, characterization and electrochemical analysis of commercially available Ti felts coated with Pt/Ir catalyst for water splitting. Anodic oxidation of the Ti felts leads to the formation of a TiO2 nanotube layer, which increases the catalytic surface area. A minimization of catalyst loading is achieved by atomic layer deposition (ALD), whereby both catalysts, platinum and iridium, are deposited in an alternating manner along the inner walls of the nanotubes. Microscopic investigation and energy-dispersive X-ray mappings indicate a homogenous coating of platinum and iridium particles inside the tubes. The electrocatalytic performance towards oxygen and hydrogen evolution from water is investigated by cyclic voltammetry and steady-state electrolysis for different quantities of platinum and iridium in an acidic medium. A catalyst loading of 42 µg/cm2 results in a current density of J = 26 mA/cm2 (at an overpotential η = 0.49 V) for the oxygen evolution and J = −32 mA/cm2 (η = −0.38 V) for the hydrogen evolution reaction, which corresponds to an electrocatalytic activity of 630 A/g and 920 A/g, respectively.

Resume : In this review lecture several examples will be shown about how various nanostructured photocatalysts can be obtained by atomic layer deposition (ALD), based on our own experience. The advantage and disadvantage of ALD films on the photocatalytic activity will be discussed. By combining electrospinning and ALD, Vis or UV active photocatalysts were prepared, e.g. WO3/TiO2, ZnO/TiO2 and TiO2/ZnO core/shell nanofibers, TiO2 nanotubes. By using sol-gel and ALD, SiO2/TiO2 core/shell photocatalytic nanoparticles were obtained. Photocatalysts based on biological substrates were also manufactured by ALD, e.g. TiO2 coated lotus leaves with both superhydrophobic and photocatalytic activities. C60, graphene oxide, polymer and carbon aerogels, carbon nanospheres, PMMA nanoparticles coated with ALD ZnO, TiO2 and Al2O3 oxide layers and particles are examples for carbon and polymer nanostructure based photocatalysts. On the previously mentioned substrates, amorphous and crystalline TiO2, ZnO and Al2O3 thin films were grown by ALD at various temperatures. While TiO2 is considered to have photocatalytic activity only in the crystalline state; unexpectedly, we observed that when TiO2 was deposited in amorphous form on organic and biological substrates, i.e. lotus leaf, C60-OH, GO, graphene oxide or PMMA, the amorphous TiO2 layer clearly exhibited photocatalytic property.

Resume : In the last fifteen years, a large number of new ionic liquid applications have been introduced to the field of catalysis. Many of these build successfully on the unique property profile offered by these low melting salts, such as e.g. extremely low volatility, high solution power for organometallic complexes and polar compounds, tunable coordination properties and suitable wetting properties. It has been demonstrated for many catalytic transformations [1,2] that the use of liquid salts enables processes of much higher efficiency. Rigorous attempts to minimize the amount of ionic liquid that is required to create a certain, desired “ionic liquid performance” has led to the development of “Ionic Liquid Thin Film Technologies”. The lecture will present novel preparation methods, characterization techniques and application scenarios of ionic liquid thin film materials for catalysis. It will highlight new catalytic cascade reactions using Supported Ionic Liquid Phase (SILP) catalysts and will give recent insights to the nature of the IL film in operating SILP systems. Moreover, the modification of heterogeneous catalysts by ionic liquid and molten salt coatings (SCILL concept) will be discussed for technically relevant catalytic transformations in particular selective hydrogenation reactions [3]. References [1] S. Werner, M. Haumann, P. Wasserscheid, Reviews of Chemical and Biomolecular Engineering, 1, 203-230 (2010). [2] H.-P. Steinrück, P. Wasserscheid, Catalysis Letters 145, 380-397 (2015). [3] T. Bauer, V. Hager, M. B. Williams, M. Laurin, T. Döpper, A. Görling, N. Szesni, P. Wasserscheid, M. Haumann, J. Libuda, ChemCatChem, 9, 109-113. (2017).

Resume : The ability to electrolyze water into its elements in benign conditions at low cost will imply the exclusive use of inexpensive, abundant materials, instead of the most advanced catalysts. Here, we demonstrate that iron oxide, the most abundant and least expensive transition metal compound, can be used as a catalytically active surface for the four-electron water oxidation to O2 at neutral pH, which represents the kinetic bottleneck of the overall reaction. We optimize nanotubular iron(III) oxide electrodes for catalytic proficiency in this reaction. They are prepared from anodic alumina templates coated with Fe2O3 by atomic layer deposition (ALD). Scanning He ion microscopy, X-ray diffraction and Raman spectroscopy characterize the morphology and phase of samples submitted to various treatments. These methods document the contrasting effects of thermal annealing, on the one hand, and of electrochemical treatment, on the other hand. The electrochemical performance of the corresponding electrodes is quantified by steady-state electrolyses and electrochemical impedance spectroscopy. A rough and amorphous Fe2O3 with phosphate incorporation proves to be optimal in the water oxidation reaction and yields an effective turnover increase by a factor of 1000 with respect to a smooth, planar Fe2O3 surface. Further improvement is reached by the addition of iridium in minute amounts (<5 ALD cycles) on the Fe2O3 surface.

Resume : With the renewed interest in solar fuels, carbon dioxide reduction reaction (CO2R) has become a topical subject of interest in the last years. In this context, catalyst coated electrodes based on gas diffusion electrodes (GDE) structures are one of the most interesting option as it allows increased number of active sites on the catalyst facilitating, at the same time, CO2 adsorption across the porous network of GDE structure. In this work, we report on electrochemical reduction of CO2 (CO2R) with copper islands formed by controlling the duty cycle of the pulsed current electrodeposition (PCE) on gas diffusion electrodes (GDE). PCE exhibited different particle morphology and improved coverage of GDE compared to continuous electrodeposition (CE). Cu islands with smaller radius size (r ~ 350 nm) promoted catalytic activity towards formate (HCOO−) production whereas larger islands (r ~1 µm) increased that of the carbon monoxide (CO). Enhancement of C1 catalytic activity of Cu nanoparticles gives inversely proportional trend with particle radius for HCOO− path. It corroborates the relevance of tuning catalyst size to improve activity and selectivity of metal nanoparticles pointing out that HCOO- formation is easier on edge and corner sites than on terrace sites on copper electrocatalyst.

Resume : Metal phosphides have attracted a research attention as anodes for lithium-ion batteries (LIBs) due to a strong covalent character of M-P bond resulting in an overall lower insertion potential compared to their oxide counterparts. In vanadium-phosphorus system, the VP showed the graphite-like topotactic intercalation reaction with Li+, exhibiting excellent cycling behavior. The VP2 showed the higher capacity than VP by forming the amorphous Li-V-P ternary phase during the electrochemical reaction with Li+, but it suffered a rapid capacity fading. The V4P7, intermediate compound between VP and VP2, is expected to show the intermediate electrode performance between VP and VP2 in terms of specific capacity and cycle retention. In this study, 100 nm-sized V4P7 nanopowder was synthesized by a high energy milling and its electrode performance as an anode for LIBs was firstly investigated. V4P7 showed the insertion reaction and delivered the high discharge and charge capacities of 1035 and 882 mA h g-1, respectively, with a high Coulombic efficiency of 85% at the current density of 100 mA g-1. Furthermore, V4P7 nanopowder was encapsulated with carbon to enhance the electrical conductivity and retain the structural integrity during lithiation/delithiation. The conformal carbon coating was achieved through polymerization of dopamine and subsequent carbonization. As-fabricated core-shell V4P7@C nanocomposite electrode exhibited the much improved high rate capability and long cycle stability.

Resume : Lithium ion batteries (LIBs) represent an attractive energy storage technology. Compared to graphite, which is used as the negative electrode in commercial LIBs, SnO2 stands out for its much higher theoretical specific capacity (782 mAh g−1) at quite negative potential for lithiation. However, the volume expansion of SnO2 is around 300%, which causes electrode fracture and pulverization, and thereby, a drastic loss of capacity. We present arrays of parallel SnO2 nanotubes as a novel LIB platform. The tubular shape is designed to have sufficient space for volume expansion and reduction during charging and discharging. Therefore, electrode pulverization and capacity loss in anodes can be adequately avoided and overcome its poor cycling performance. To gain SnO2 nanotubes, anodic aluminum oxide membranes serve as the matrix. Afterwards SnO2 is deposited onto the walls of the deep, straight, cylindrical pores of those membranes via atomic layer deposition (ALD). An electrical contact consisting of gold is sputtered subsequently. The electrodes assembled into complete lithium ion batteries are then tested for electrochemical characterization by cyclic voltammetry, charge-discharge, and electrochemical impedance spectroscopy. A drop of discharge capacity happens between the first and second cycle, due to the formation of SEI layer. The capacity remains stable afterwards. The tubular morphology is retained upon cycling, as demonstrated by scanning electron microscopy. The performance of SnO2 anode can be controlled by varying the thickness of SnO2 on the template pores. Further study will be focused on optimizing the nanoscale geometric parameters of the system, aiming at maximizing capacity while minimizing capacity loss.

Resume : Sb2S3 is a promising material for solar cell applications due to its high absorption coefficient, abundance of its constituents Sb and S. Sb2S3 thin films were prepared by a two-step process. Sb2S3 layers were deposited by low-cost ultrasonic spray pyrolysis on glass/ITO/TiO2 substrates at 200-250°C in air from a methanol solution of SbCl3 (15-60 mM) and thiourea (SC(NH2)2) in Sb:S molar ratio 1:3-1:6. Layers were heat treated in air at their deposition temperatures up to 30 min or at 300°C for 5 min in vacuum, N2 or H2S. The morphology, chemical composition, structural and optical properties of Sb2S3 layers were characterized by SEM, Raman, XRD and UV-Vis methods, respectively. Heat treatment of Sb2S3 thin layers in N2, H2S and vacuum improved crystallinity, density and substrate coverage. Sb2S3 layer thickness increases proportionally to precursor concentration and sprayed volume. Heat treatment in H2S improved S:Sb ratio in Sb2S3 layers from 1.1 up to 1.4. Crystalline Sb2O3 was detected by Raman in vacuum heat treated samples deposited at 220°C from 15 mM 1:3 Sb:S solution and in all air heat treated samples due to oxidation. Sb2S3 films obtained after deposition at 200-250°C and annealing were tested in gl/ITO/TiO2/Sb2S3/P3HT solar cells, showing up to 5.5% power conversion efficiency. Flat single-phase crystalline Sb2S3 films with band-gap 1.7 eV were obtained by low-cost ultrasonic spray pyrolysis followed by post-deposition heat treatment.

Resume : ZnO, is an intensively studied semiconductor with a 3.3 eV band gap at room temperature, what makes it a promising candidate for photovoltaic (PV) applications. Most of the studies concentrate on the use of ZnO as a transparent electrode (transparent conductive oxide (TCO)). Other possible applications include the use of ZnO as a buffer layer and/or a n type emitter in Si- based solar cells, as we demonstrated recently [1-3]. In our work we demonstrate a n-type ZnO structure with a 3D ZnO-nanorods as an alternative low cost materials for construction of efficient ZnO/Si solar cells. Zinc Oxide and ZnO:Al (AZO) films were deposited by atomic layer deposition method (ALD). The 3D zinc oxide nanorods were grown by a hydrothermal method. Various versions of PV cells of the same architecture were investigated, with a thickness of silicon wafers varied between 50 and 200 μm. Electrical parameters of the wafers are 2 Ωcm and a hole concentration is 10^15 cm^-3. For 200 μm thick solar cells, we received light conversion efficiency up to 14%. For thinner silicon films the Jsc value decreases from 38 mA/cm2 to 30 mA/cm2, whereas the Voc remains similar, of about 500 mV. The solar cells efficiency varies between ~10% for the cells constructed on the thinnest Si wafers. This work was partially supported by the National Science Center (Decision Nos. DEC-2012/06/A/ST7/00398), and (Wroclaw group) by the National Laboratory of Quantum Technologies (POIG.02.02.00-00-003/08-00) and Statutory grant 0401/0009/17. 1. R. Pietruszka, et al., Solar Energy 155 (2017) 1282-1288. 2. R. Pietruszka, et al., Solar Energy Materials & Solar Cells 147, (2016) 164-170. 3. R. Pietruszka, et al., Solar Energy Materials & Solar Cells 143, (2015) 99–104.

Resume : Sb2S3 as an emerging photovoltaic (PV) absorber has successfully been tested as thin films, nanoparticulate layers and coatings on nanostructures [1–3], a versatile candidate at the forefront of the search for a new potential among stable, inorganic optical absorbers. Chemical Spray Pyrolysis is an ultra-fast, no-waste route with no demand for vacuum or inert gas for deposition of metal-oxides and -sulfides while the powerful ultrasonic spray pyrolysis (USP) has only recently been used to produce Sb2S3 for PV [1,2]. We aim to reach new heights by optimizing the deposition parameters of Sb2S3 when grown on a TiO2 underlayer, both deposited by USP, completed by P3HT layer as a p-conductor, and Au contacts for PV evaluation by I-V curve and EQE measurements. With power conversion efficiency of 5.5 % under a solar simulator for a cell with a contact area of 1.7 mm2 and 3.3 % from an active area of 0.9 cm2, the results speak of competitive results with expected yet surmountable challenges for up-scaling. By fine-tuning a two-step process for producing crystalline Sb2S3 absorber in a planar style we aim to blueprint a method for a conformal coating in a 3D underlayer (ZnO nanorods by electrochemical, spray, or chemical bath, covered by TiO2 grown by USP). 1.Kärber et.al. Beilstein J. Nanotechnol. 2016, 7, 1662–73. 2.Gödel et.al. Chem. Commun., 2015, 51, 8640. 3.Parize et.al. J. Phys. Chem. C, 2017, 121 (18), 9672–80.

Resume : Dye-sensitized solar cells (DSSC) are the best known of the third generation type of solar cells. Some types of SSC are fabricated on solid basis, presenting the advantage of a better stability. A promising type of SSC is the extremely thin absorber (ETA) solar cell.1 Sb2S3 has received increasing attention recently as ETA material due to its unique properties (α ≈ 1.8 × 105 cm-1; Eg = 1.7 eV). Typically, Sb2S3 is synthesized by chemical bath deposition methods on TiO2 based electrodes. This method causes the formation of antimony oxides within the Sb2S3 layer which implies the formation of carrier traps in the bandgap. In this work, we use ALD to coat the TiO2 electrodes. This technique presents the advantages of depositing pure Sb2S3 and layers with very uniform thicknesses. However, the purity of the Sb2S3 and the mismatch of the crystalline structures between Sb2S3 and TiO2 cause dewetting during the change from amorphous to stibnite phase. This dewetting leaves large areas of TiO2 exposed after annealing and produces the formation of large stibnite crystals. However, adding an interfacial layer of ZnS circumvents this difficulty, allowing for the formation of pure stibnite layer with highly uniform thickness.2 These structures are used to form p-i-n heterojunctions with organic polymers, presenting excellent I-V characteristics under simulated solar light. 1. H. Wedemeyer, et al., Energy Environ. Sci.(2013) 6, 67-71 2. Y. Wu, et al., J. Mater. Chem. A, (2015), 3, 5971-5981

Resume : An all-oxide photovoltaic approach is very attractive due to the chemical, mechanical and thermal stability of many metal oxides which can often be prepared by cost-effective and scalable techniques. Ferroelectric perovskite oxide based PV cells arise as an innovative and promising alternative to current PV technology. These materials are of particular interest as they provide unique routes to spontaneously separate excitons achieving extremely large photovoltages that can exceed the band gap. Enhancing the abnormal photovoltaic effect in ferroelectric perovskite oxide materials by judicious engineering of the bandgap offers unprecedented opportunities for this class of materials to build PV devices with increased power conversion efficiency. Here we propose novel ideas combining chemical solution deposition and atomic layer deposition to control cation composition in ferroelectric BiFe1-xCoxO3 thin films (x= 0, 0.2, 0.3) to ultimately tune the bandgap and overall absorption to optimally match the full solar spectrum. Advanced XRD characterization and atomic-resolution imaging of cation-doped BFCO thin films demonstrates the successful incorporation of cobalt atoms in the BFO structure resulting epitaxial thin films. Also, the effect of cobalt substitution on the chemical environment of Bi and Fe atoms has been investigated by x-ray photoelectron spectroscopy. Finally, the effect of Co substitution on remanent ferroelectric polarization (35 μC/cm2 for pure BiFeO3) and quantum efficiency will also be discussed.

Resume : The results of modeling of bimolecular interactions on the surface are presented in this article. Statistical properties are calculated for the investigated system. Annihilation processes reduce to regulation of matrices and to formation of stable fractal clusters with homogeneous porosity. Research of external action influence processes on the evolution of materials structures is one of the fundamental tasks with important applied significance. The processes such as energy transfer of electron excitation are nonlinear. They proceed in open systems and result in their structural recombination and spatial reorganization of configurations of their components. Owing to the spatial separation of interacting particles in clusters arise from the same type of defects. Such structures are called multifractal objects or inhomogeneous fractal sets containing subsets of different fractal dimensions. For thorough investigation of such nonlinear processes in open systems we applied fractal geometry methods. Annihilation reaction in donor-acceptor pairs takes place at approach of reagents up one interstitial distance equal quenching sphere radius. Coverages of the surface by each sort molecules were equal σ1= σ2=0,4%. At selected coverage of the surface to annihilation act electron excitation energy transfer on the donor system is possible. Usable method allows simulating matrices with accidental initial distribution of acceptor molecules and different type of initial distribution of donor molecules: chaotic, multifractal, cluster, and also to conduct an analysis of annihilation interactions kinetics subject to change of fractal properties of matrix and degree of its order. Initial chaotic distribution was obtained by accidental random choice of points coordinates on the plane lattice by the instrumentality of random number generator. Multifractal distribution was obtained from chaotic by process of elimination of interacting pairs and spatial division of reagents. Criterion of multifractal formation on the model surface served decrease of system entropy. At generation of cluster distribution coverage of the model surface and corresponding to the surface number of accidentally distributed non-intersecting connected clusters given size were determined. Distance between nearest molecules in connected cluster is determined by maximal distance on which effective energy transfer between them is possible. Reagents distribution on the surface is analyzed on basis of multifractal analysis data. Multifractal analysis allows finding out general regularities of formation, stability, decay processes of ordered temporal and spatial structures. The annihilation kinetics decreases at transition from chaotic to cluster distribution of donor molecules as a result of excitation localization in the range of cluster. Energy transfer and annihilation processes reduce to formation of stable fractal clusters on the surface and order parameter increase, regulation time of matrix depends on reagents initial distribution.

Resume : A suspension of poly(methyl methacrylate) PMMA polymer beads is used as an unique templating agent for forming a scaffolded layer of TiO2 with a control of porosity size by molding process. The goal of this work is to prepare a TiO2 n-type semiconductor porous film to promote the growing large crystals hybrid of lead halide perovskite for a photovoltaic application and enhance interface quality and reduce defects. Moreover in order to probe an enhancement of the scaffolded layer conductivity a sol-gel mixture of titanium and tin in propionic acid was successfully used and deposited by spin-coating technique. This process using polymer beads molding is carried out essentially by a chemical way. SEM/EDX on resulting samples show that a large pore size (up to 100 nm) scaffold layer can be prepared according to the beads diameter (from 100 nm to 800 nm). The XRD patterns correspond to the anatase phase for TiO2 and the casserite phase for SnO2. This two phases separation occurs on several morphological way from perfect mixture of TiO2 and SnO2 nanocrystal surrounding the porosity to a mixture of large SnO2 spherical particles with TiO2 nanocrystal constituting the voids walls. The study is focused essentially on morphology analyses of the porous layers for different preparation conditions and not on complete cells in the aim to demonstrate a simple and cheap way to obtain a porous film of n-type semi-conductor by sol-gel process. We also intend to modify the conductivity of moulded scaffold using Ti-Sn mixed sol-gel solution as TiO2–SnO2 moulding precursors.

Resume : The self-organized 1D TiO2 nanotubular layers have attracted considerable scientific and technological interest over the past two decades, all motivated by an expected great performance in the range of applications including photo-catalysis, solar cells, hydrogen generation and biomedical uses.1,2 The synthesis these nanotubular layers has been carried out by a conventional electrochemical anodization of Ti sheet that is very simple and a low-cost method. Except the 1D character, these nanotubes possess unique features such as tunable dimensionality, structural flexibility, unidirectional electron transport through nanotube walls, chemical and mechanical stability and biocompatibility. One of the major application targets of TiO2 nanotubes has been their utilization as scaffolds or templates for deposition of secondary materials towards new applications. For instance, tailoring the TiO2 anode chromophore inter-face can increase the efficiency of the cells, such as DSSC3 and perovskite-based solar cells4. The enhancement can be achieved by increasing the interfacial surface area between the chromophore and the TiO2 oxide in order to facilitate charge separation. Unlike randomly ordered mesoporous TiO2 support, ordered nanostructures, such as self-organized TiO2 nanotubes with high aspect ratio or TiO2 nanowires, offer the advantage of directed charge transport and con-trolled phase separation between donor and acceptor materials and thus they seem to be one of the most promising nanoscale solar hybrid technologies.5 Numerous techniques were utilized for this purpose, such as for example wet chemical and electrochemical routes or physical deposition techniques.6 However, recently it has been shown that the utilization of Atomic Layer Deposition (ALD) can extend the functional range of TiO2 nanotubes by homogenous coatings or decoration of tube interiors by a secondary materials.6-13 ALD is the only technique of choice to coat in particular high-aspect ratio nano-tube layers. Overall, the deposited coatings influence strongly photo-electrochemical,7-11 chemical, mechanical and structural12 properties of nanotube layers. The presentation will be focused in detail on TiO2 nanotube layers of various aspect ratios coated by CdS using ALD. Experimental details and some very recent photo-electrochemical and structural characterization of a new type of heterostructured photo-chemical half-cells11,14 will be presented and discussed. REFERENCES [1] J. M. Macak et al., Curr. Opin. Solid State Mater. Sci., 2007, 1-2, 3-17. [2] K. Lee, A. Mazare, P. Schmuki, Chem. Rev., 2014, 114, 9385-9454. [3] P. Roy et al., Nanoscale, 2010, 2, 45-59. [4] X.Gao et al., Chem. Commun., 2014, 50, 6368-6371. [5] B. O´Regan and M. Grätzel, Nature 353 (1991) 737. [6] J. M. Macak, Chapter 3 in: D. Losic and A. Santos, Electrochemically Engineered Nanoporous Structures, Spring-er International Publishing, Switzerland, 2015. [7] H. Sopha et al., Appl. Mater. Today, 2017, 9, 104-110. [8] Q. Gui et al., ACS Appl. Mater. Interfaces, 2014, 6, 17053-17058. [9] A. Ghobadi et al., Sci. Rep., 2016, 6, 30587. [10] S. Ng et al., Adv. Eng. Mater., DOI: 10.1002/adem.201700589 [11] M. Krbal et al., Nanoscale, 2017, 9, 7755-7759. [12] R. Zazpe et al., Langmuir, 2017, 33, 3208-3216. [13] L. Assaud, et al., ACS Appl. Mater. Interfaces, 2015, 7, 24533-24542. [14] R. Zazpe et al., xxxxxx, 2018, submitted.

Resume : There is an increasing interest for concentrated solar power (CSP) systems which can work at temperatures higher than 1000°C to optimize the yield. Current systems generally utilize high temperature metallic alloys such as Inconel, or bulk and porous ceramics such as alumina or silicon carbide. However, high temperature causes the degradation of current receiver materials when exposed to air. The present study explores the behavior of ceramic coatings on refractory alloys which have been developed for aerospace or gas turbine engine applications. Contrarily to coatings in gas turbine engine, they must have a high thermal conductivity to ensure heat transfer to the fluid. Aluminum nitride and silicon carbide coatings, deposited by chemical vapor deposition at 1100-1200 °C, were selected for their high thermal conductivity, low thermal expansion coefficient, high temperature stability and their ability to develop thin and stable alumina or silica scales at 1000 °C. Molybdenum based refractory alloys were chosen for their low thermal expansion and low creep rate and weldability when compared to bulk ceramics. FeCrAl alloys were also selected for their high resistance to oxidation although they have higher creep rate. Thermogravimetric measurements and accelerated cyclic oxidation tests as well as emissivity measurements made in Odeillo solar furnace facilities demonstrate the potential of AlN coatings on metallic alloys as materials for high temperature CSP receivers.

Resume : The deformation density and structural geometry for lithium niobate, LiNbO3, at low and room temperature, are derived from single crystal high resolution X-ray diffraction measurements. The geometry of LiNbO3 and molecular packing arrangement are analyzed and compared with literature data. Data was collected at 120 K and 293 K for a spherical LiNbO3 crystal using a CAD4 Enraf Nonius four-circle diffractometer equipped with a low temperature device using liquid nitrogen. The lithium niobate is an optical uniaxial crystal, ferroelectric compound known for its interesting properties in the non linear optical domain. The data processing was carried out using the formalism as described by Blessing. The structure refinement was carried out using the program XD (Koritsanszky, T., Howard, S., Richter, T., Su, Z., Mallinson, P. R. & Hansen, N. K. (2003). The reliability factors obtained at the end of the refinement are 4% for the room temperature and about 3% for the low temperature investigation

Resume : Chemical coating, an effective doping modification method, was employed to fabricate fine-grain BaTiO3-based ceramics. Based on the consideration of subsequently using base metal as inner electrodes in multilayer ceramic devices, green bodies are generally sintered in reducing atmosphere, which generates more charged point defects and thus affects the electric properties. According to the elements distribution analysis, Al element is greatly enriched in the grain boundary and shell region. Coating Al2O3 achieves not only a smaller grain size and narrower distribution but also a higher breakdown strength, discharge energy density and energy efficiency at ambient temperature. In addition, temperature dependences of dielectric and energy storage properties under a same field were also investigated. Over the whole measuring temperature range, the sample with Al2O3 remains higher discharge energy density and energy efficiency.

Resume : Photo-induced curing of coating materials is applied to various application, and the designing of the reaction based on the photochemistry is essentially important in developing high-performance materials. However, most of the photochemical reactions of practical coatings are usually performed in solid state matrices, and the reactions in the solid state polymers are completely different from those in solution due to the effect of restriction of molecular mobility, inhomogeniety of free volume in the matrix, and the effect of various structual relaxations. We measured the inhomogeneity of quantum yield distribution or kinetic constants of various photochemical reactions in solid state polymers. The quantum yield of hydrogen abstraction or quenching of benzophenone, one of the initiators of curing, was found to have wide distribution corresponding to the free volume distribution of matrix. It is found that the magnitude of fast decaying component increased in the lower temperature region, which is contrast to the apparent expectation that the quenching or reaction is restricted by the free of molecular motion. The data suggest that local reactions in nano scale region are accelerated by the restriction of matrix relaxation. Inhomogeniety of kinetic constants of other photoreactive molecules will be also discussed.

Resume : One of the cheapest architectures for perovskite solar cells (PSC) is the so-called carbon PSC (C-PSC), which is fully printable and stable for more than a year under 1-sun exposure. The architecture is based on a triplo-mesoscopic scaffold (titania, zirconia and carbon) and the infiltration of perovskite from the top electrode layer. Examples of series-connected modules with the C-PSCs are already reported in the literature. However, the ratio between the photovoltaic active area and total area required to make a device, commonly called geometric fill factor (g-FF), is less than 50%. The reported modules are based on an accurate registration of each layer to connect cells on the same substrate in series using precision printing. This method requires a loss of space to properly overlap each layer. The scribing method, by contrast, significantly reduces the lost space allowing much higher g-FF. Chemical mapping of the scribe can confirm complete material removal. In this work, registration and scribing methods have been studied. The interconnections are characterized in terms of morphology and chemical composition. For the scribing-based modules, the material removal method is automated to avoid damaging of the underlying conducting layer. This method enables a significant decrease in interconnection distance to 0.1mm with similar. A systematic study to optimise the interconnection distance in terms of both device performance and g-FF will be presented.

Resume : Water oxidation is considered the bottleneck in the development of an efficient and cost-effective water splitting technology. State-of-the-art water electrolyzers are still far from being competitive with steam reforming, the cheap and well-established hydrogen production scheme from fossil fuels. One of the challenges resides in substituting the expensive noble metal catalysts by earth-abundant counterparts while maintaining the efficiency and performance required for technological applications. Inexpensive transition metal oxides are very competitive catalysts for the oxygen evolution reaction (OER) but exclusively in alkaline media. We have discovered in our labs the unparalleled OER activity offered by Prussian blue analogues. These coordination polymers are robust in the solid state, stable and active in a large pH range (0 < pH < 11), appearing as a unique alternative based on abundant and inexpensive metals. In this communication, we will present our latest results and advances in the processing of these coordination networks for their implementation into water splitting devices.

Resume : Magnetoresistive (MR) sensors are widely used in day-to-day applications, where the MR magnitude is an important figure of merit. In this work we present the results of La1-xSrxMnyO3±δ films, exhibiting colossal magnetoresistance effect, which are used for the development and production of advantageous B-scalar sensors capable to measure pulsed magnetic field amplitude independently on its direction. Pulsed-Injection Metal-Organic Chemical Vapor Deposition technique was used in order to grow epitaxial and nanostructured La1-xSrxMnyO3±δ films with tunable properties like sensitivity to magnetic field and magnetoresistance anisotropy (MRA). For this reason, different type substrates (epitaxial, ceramic and amorphous) was used and the thickness of the films was varied from 30 to 480 nm. It was obtained that keeping a constant chemical composition in the precursors solution, the Sr amount in the thinner films (30-160 nm) was lower in comparison with the thicker ones. Therefore, the additional Sr source was applied at the early deposition stage in order to change the gradient of Sr. It was found that electrical resistivity decreased while the metal-insulator transition temperature increased with the thickness of the films. The MR of the investigated films was measured in permanent (0.7 T) and pulsed (20 T) magnetic fields. The optimal substrate, thickness and film composition was chosen for the development of magnetic field sensors exhibiting largest MR and lowest MRA values.

Resume : Caused by unique properties of organic-inorganic hybrid perovskite films, the patterning process is very challenging. In this study, novel method for etching of perovskite film is suggested using atmospherically hydrogen-containing plasma treatment. It is illustrated successful eating of methylammonium triiodideplumbate (CH3NH3PbI3) perovskite films on glass substrates. Perovskite layers are processed for various times between 2 s and 300 s. Based on the transformation of film’s morphology upon treatment time three regions are distinguished; i.e. short (less than 10s), medium (up to 180s) and long (more than 180s). Although onset of the early modifications is observed after 10 s treatment the bulk characteristics of the film remain mainly the same. After 30 s treatment nano-sized particles are observed in the entire film. When plasma treatment performed longer period i.e. 180 and 300 s, some particles are agglomerated forming relatively large clusters. The morphological and chemical properties of the plasma-processed films are analyzed using various analytical tools such as scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive X-ray spectroscopy coupled with SEM or TEM (EDS-SEM and EDS-TEM), and x-ray photoelectron spectroscopy (XPS).

Resume : In modern times when sustainable fuel production and harmful emission reduction is high priority for lowering global environmental change, it is imperative to find effective ways to combine aforementioned activities. CO2 is one of such emission gases, found in many industries. Food industry produce relatively pure CO2, it could be separated and reformed into useful chemical products such as methane. To find most straight forward way of electrocatalytic CO2 reduction it is necessary to find proper spectroscopic investigation methodology for in situ measurements. In this work the FTIR spectroscopic investigation of metal catalysts influence on CO2 electrocatalytic reduction in closed catalysis system is discussed. Closed catalytic system was created for electrolyte flow through investigation of metal catalyst influence on CO2 reduction. Various catalytic properties of cathode were investigated and compared with photocatalytic CO2 reduction on anodic nanostructured TiO2 with Ag nanoparticle catalyst. The financial support of H2020 project CO2EXIDE is greatly acknowledged.

Resume : In recent years there has been interest in the use of laser technology for the realization of corrosion-resistant surface on engineering alloys based on steel. High-energy laser treatment is promising direction for surface hardening of materials and increasing operating characteristics of products. Investigated regularity of structure formation and surface layers of steel alloys with Ti (0.7÷1 vol.%) and Cr (1.1 ÷2 vol.%) after laser treatment with reactionary saturating agents (elements N, C) and after combined laser, chemical and thermal treatment in complex reactionary nitrogen- and carbon media. Model concepts concerning formation processes of such complex structures during of high concentration gradients, temperature and mechanical stresses fields fast changing were proposed. These model concepts explain formation of complex combinations of nanophase structures which provide an increasing of microhardness in zones of laser treatment in modes of high-speed melting and quenching of nearsurface layers material. Representations model are offered ideas about peculiarities of the formation of nonequilibrium local inhomogeneous structures with dispersed interstitial atoms and properties surface layers of iron alloys after laser chemical and heat treatment in the reaction medium with different chemical composition and physical state. It is shown that processes on the outer surface of the micron and submicron layers, thermodynamically determine the patterns of diffusion in volume of material.

Resume : An important direction of modern material science is the creation of a complex of increased operational characteristics of the surface due to changes in its structure and phase composition. Electric-spark alloying is a promising method of surface treatment of steels and alloys. This method provides for the formation of hardened coatings with the use of electrodes from any conductive materials, is an environmentally friendly, energy-saving and resource-saving process. The paper studies the change in the structure, phase composition, microhardness and wear resistance of alloyed layers obtained on the surface of Steel 45 after electric-spark alloying in the sequence of Ti-C-Zr and Zr -C-Ti in an atmosphere of argon and air. The possibility of creating multicomponent functional coatings by the method of electric-spark alloying layer with carbide-forming elements - titanium and zirconium, as well as graphite in air and argon atmosphere is shown. The influence of the atmosphere and the sequence of electric-spark alloying on microhardness and wear resistance of the surface layers of Steel 45 was revealed. It was established that electric-spark alloying in an argon atmosphere leads to the formation of alloyed layers with a thickness of 45-70 microns and a microhardness of 10.5 GPa than electric-spark alloying in air atmosphere thicknesses of 15-30 microns and a microhardness of 7.5 GPa. The wear resistance of the surface of steel 45 after electric-spark alloying anodes Zr, C, Ti increases in 6-7 times compared with the surface without processing. Such properties are due to the formation of dispersed carbide, carbonitride and intermetallic phases in the conditions of ultra-fast heating, melting and cooling processes.

Resume : Bismuth vanadate is one of the most promising photocatalytic material. Its energy band gap equals to 2.4-2.5 eV allows the significant part of a sunlight to be absorbed. Photoexcited charge carriers can be utilized for both, water splitting and photocatalytical degradation of hazardous waste. The main drawback of monoclinic BiVO4 is the low mobility of charge carriers. It leads to the low efficiency of electron/hole separation and poor kinetics of water oxidation and oxygen evolution. To obtain the high photocurrent of water photooxidation, high anodic potential are required. There are many strategies of BiVO4 performance enhancement i.a. modification of BiVO4 surface with oxygen evolution catalyst. It was reported that Prussian blue analogues (e.g. cobalt hexacyanoferrate) exhibits catalytical properties towards oxygen evolution reaction. Thus, in this work, cobalt hexacyanometallates were deposited onto BiVO4 surface. Modified electrodes were tested as photoanodes for photoelectrochemical water splitting under simulated solar light illumination. The enhancement of photoelectrochemical activity was obtained. KT acknowledges the National Science Centre of Poland, NCN, for financial support under contract no 2017/01/X/ST5/00172.

Resume : Composites consisting of bismuth vanadate have shown advantage over pure BiVO4 films in terms of efficiency during photocurrent generation in photoelectrochemical water splitting in PEC devices. Consecutive innovations that are being described in literature successfully help to mitigate main disadvantage of this material – high recombination rate of electron-hole pairs, proving that photocatalyzed water decomposition may become even more efficient method for production of hydrogen fuel. In this work, system containing cobalt hexacyanoferrate (C6CoFeN6) embedded into polymer matrix was tested as a photoanode. Modification was meant to prevent recombination of electron-hole pairs increasing efficiency of the water photooxidation process. Bismuth vanadate electrodes were modified by electrodeposition of cobalt hexacyanoferrate built in polypyrrole (PPy) or poly(3,4-ethylendioxythiophene) (PEDOT). Prepared composites were subjected to pyrolysis in order to decompose polymer thermally. Photoelectrochemical and electrochemical performance, as well as morphology of photoanodes of different design were tested. Films were polarized in the dark and under illumination in range 0 – 1.2 V vs Ag/AgCl (0.1M KCl) Measurements allowed for comparison of photocurrents generated by photoanodes. KT acknowledges the National Science Centre of Poland, NCN, for financial support under contract no 2017/01/X/ST5/00172.

Resume : Dion-Jacobson series with the general formula M[An-1BnO3n+1] with n=3 (M: alkali metal ions, B: alkaline earth metal ions) are new members of two-dimensional layered perovskite compounds.The alkali metal ions in the interlayer positions proceed ion-exchange reactions so that the physical property of the compound is tuned by ordering the different cations between the interlayer spaces. The cations in the intralayer position can also be varied by supplying different amount of lanthanides instead of B2+ alkaline earth metal so that the luminescence properties can be examined. Beside this, the nanosheets, which are very important because of their large surface area, can be fabricated with the help of intercalation and exfoliation reactions between the layers. In this study, triple layered CsCa2Ta3O10 powders doped with Pr, Er, Eu, Sm at 10 percent of Ca amount was prepared by solid state reaction and polymerized complex (PC) method. Characterization of the main powders and protonated forms of them was conducted by XRD, Uv-Vis Diffuse Reflectance and Photoluminescence Spectrophotometer. And also, the effect of doping different lanthanides on the band gap value has been examined by drawing Tauc Plot which are supported by the XPS measurements. The protoned form of CsCa2Ta3O10 shows shifting to higher 2Θ value which proves that the interlayer distance between the layers has decreased and H-ion exchange step was completed. After H-ion exchange reaction, the Ethylamine intercalation reaction is followed to extend the distance between the layers. Intercalation reaction is nothing but an acid-base reaction between the H+ and ethylamine ions. To dry H-exchanged form, the room temperature is preferred to prevent the hydrated water from evaporating from the interlayes. Because, the amount of water between the layer also affects the intercalation reaction to become properly. The diameter of a TBA+ ion is 0.8 nm and it is larger than the interlayer distance of H-exchanged form of CsCa2Ta3O10 (around 0.2 nm). The direct exfoliation of the H-exchanged powder with TBA+ ions resulted in failure which suggests that the EA-intercalation is really essential step for proper exfoliation since the distance (d) between the layers increases with intercalation. The XRD pattern of doped samples also show the same pattern with the undoped CsCa2Ta3O10. After intercalation step, exfoliation reaction was carried out to prepare nanosheet solution. The concentration of TBA solution and the mol ratio between Ca2Ta3O10- / TBA+ are the parameters that can be tuned to achieve exfoliation step properly The best result was obtained by 1:1 TBA+ / Ca2Ta3O10- mol ratio. The size, shape and thickness of the nanoplates were examined by getting STEM and AFM images. The H-ion exchanged powder were deposited on FTO in iodine solution by electrophoretic deposition technique. The deposition has occurred on the cathode electrode by applying 20-50 V along 10-30 minute. And, the dip coating technique were conducted to deposit nanosheets onto the FTO electrodes by using cationic polymer PEI (polyethylenimine). The absorption and emission spectra of the nanosheet coated FTO were carried out to prove the existence of lanthanide atoms. The characteristic absorption and emission peaks of lanthanides were observed for each film obtained by EPD technique for powders and Dip Coating technique for nanosheets. The films doped with different lanthanides and deposited by different techniques were compared in terms of their photoelectrochemical activity. To increase photocurrent, the surface of films were coated with Cobalt-Iron Prussian Blue analogues. CoFe Prussian blue analogues were proven to act as a good catalyst for water splitting reaction. By integration of CoFe PB analogues with luminescent nanosheet films, the enhancement of photocurrent is aimed when it was compared with bare nanosheet films. Materials Research Bulletin. 34, 6 (1999). J. Phys. Chem. B. 109, 16 (2005). J. Am. Chem. Soc. 134, 38 (2012). ACS Appl. Mater. Interfaces. 9, 37671-37681 (2017).

Resume : Combination of porous silicon as a nanotemplate and high-resolution electron beam lithography was used to fabricate superconducting NbN nanonetworks with a very small number of interconnected nanowires with diameter of the order of 4 nm. The method is easy to control and allows the fabrication of devices, on a robust support, with electrical properties close to a one-dimensional superconductor. The PS templates were fabricated by an electrochemical anodic etching. The thickness of the anodized silicon layer was 1.5 mkm and the average diameters of the pores was 5, 7.5 and 10 nm. NbN ultrathin films were deposited by magnetron sputtering. Samples were then patterned by high-resolution EBL in strips with width in the range of 60 – 320 nm and length in the range of 270–1370 nm. Temperature dependencies of bridge resistance confirms that a percolative path is preserved along the whole strips and that superconductivity is achieved. These results have a good correlation with simulation data. Combining the PS template with high-resolution EBL, it is possible to fabricate a superconducting network consisting of a very small number of NbN nanowires. The analyzed system presents a suppression of the superconductivity at low temperatures due to the phase fluctuations of the order parameter. The main advantage of the proposed method is that it allows the creation of a quasi-1D superconductor with an effective diameter of the order of few nm that can be used in superconducting nanodevices.

Resume : Development of anti-pollution coating process technology for the installed of PV power plant PV module that possible application in the field is the purpose of this study. Most of the modules are exposed to pollutants like yellow dust and excrement of wildlife. And they significantly reduce the efficiency of the PV module. So we applied the brush coating, annealing by torch method and glass substrate which is the same material of PV module for easy field application. The characteristics of anti-pollution coatings on glass substrates using different number of annealing treatment after brush coating were investigated. The anti-pollution coating was performed on the surface of glass substrate by brush coating, the films were annealed under different number of annealing treatment. The light transmittance was measured by UV-visible spectroscopy including integrating sphere, the surface hardness and adhesion was measured according to ASTM D3363 and ASTM D3359 standards, the contact angle was measured with a contact angle analyzer, and anti-pollution characteristics according to the contact angle were analyzed. This technology can be applied directly to the installed and operated PV modules and it can be useful to improve the efficiency of power generation.

Resume : Solar water splitting has been widely investigated using various photo-absorbers with catalysts for the production of clean solar fuels. However, their poor durability of photoanode materials under oxidative environments has been raised as a crucial issue for their practical application. Recently, polyoxometalates (POMs) were suggested as a promising catalyst for water oxidation, though it is challenging to immobilize them onto photoelectrodes in a stable manner during the reaction. Here we report the immobilization of POMs onto Au/TiO2 photoanodes with an Al2O3 layer by atomic layer deposition (ALD). The Au/TiO2 heterostructure was chosen due to its strong plasmonic absorption and excellent stability in aqueous media. In this study, negatively charged [Co4(H2O)2(PW9O34)2]10– (Co4POMs) are attached to the cysteamine-coated Au nanodisks (ND) by electrostatic attraction. The Au NDs are fabricated by e-beam evaporation on a TiO2/ITO substrate using anodized aluminum oxide (AAO) as a mask. The photoelectrochemical and structural characterizations are examined before and after photoelectrochemical water oxidation. Higher photocurrent and smaller current drop over time and cycle are observed in the Al2O3-coated photoanode. Structural and surface analyses showed that Co4POMs remain after the reaction, which indicates that the Al2O3 layer can prevent the dissociation of Co4POMs on the surface during the water oxidation. Moreover, the Al2O3 layer created a depletion region at the interface, improving plasmonic hot electron transfer from Au NDs. This research provides a useful insight that the ALD protection layer can enhance the stability and performance of POM-plasmonic photoanodes for water oxidation. This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT & Future Planning (NRF-2016R1A2B4013045).

Resume : The magnetic shielding of the μT region is very important in the field of photoelectron measurement. Genially, magnetic shields made of high magnetic permeability material are used for devices and equipment affected by magnetic field less than 100 μT like Earth magnetic field. One of such materials for magnetic shield is Permalloy having relative magnetic permeability over 10,000. There are two methods of magnetic shielding. One is to install equipment in a magnetically shielded room and the other is to cover only parts which magnetic shielding must be required. In the former case, it is difficult to obtain the magnetic shielding effect for a magnetic field generated from inside a room such as an add-ons coils and power-supply unit with transformer. In addition, a cost is very high due to cover the whole room with high permeability materials. On the other hand, the later way provides a more efficient magnetic shield than the former, with not so high cost. However, in general, on vacuum equipment stainless flanges are used to connect permalloy pipes. These flanges were welded to the ends of the magnetic shields. Adjacent magnetic shields were connected with each other through two flanges. In this way, magnetic field could be reduced from 40 μT to 0.5 μT or less. However, this structure had a problem. The problem was that the flanges were made of stainless therefore the magnetic permeability of stainless steel is less than 1/100 of permalloy, the shielding effect was very small around flanges. If the flanges were made by permalloy, this would be no problem. Unfortunately, permalloy flanges are not practical way from a viewpoint of the cost. For this reason, we devised a method to improve a magnetic shielding effect even if using stainless flanges. The method was to use a magnetic shield fabric with excellent flexibility of fabric prepared by permalloy wire and covered stainless flanges with this fabric. Flexibility of permalloy fabric enabled to shield some parts with complicated shape which were difficult to cover with rigid permalloy sheet. It also became easy to adjust the effect of magnetic shield only by changing the number of turns of permalloy fabric. Because the magnetic properties of permalloy were impaired after machining processing, it was necessary to carry out magnetic anneal in vacuum furnaces. In this study influence that diameter of permalloy wire, anneal temperature, how to weave fabric of permalloy wire, and the density per unit of area of permalloy wire caused for a magnetic shielding effect was investigated. 200 - 950 °C was used for the anneal temperature. The measurement of the magnetic shielding effect was determined by inserting a magnetometer (Bartington Instruments: Mag-01 Single Axis Fluxgate Magnetometers). Surface morphology of permalloy wire was investigated by scanning electron microscope (SEM; Elionix ERA-8900FE). It was suggested that a grain boundary condition on permalloy wire influenced a magnetic characteristic greatly.

Resume : Aluminium has been used as the standard material for gas-discharge laser cathodes for several decades due to its ease of processing, shaping and low cost. Beside various established aluminium cathode production methods it is still challenging to keep the stability of working conditions during the bombardment of the aluminium surface with charged and accelerated particles with in a pressurised gas medium. The oxide layer on aluminium acts as an effective protective layer against unwanted erosion and re-sputtering. On the other hand, the uniform growth (thickness gradient and discontinuity in the morphology) of the oxide layer leads to inhomogeneous charge distribution which reduces the life-time of the cathode significantly. In addition, the selective sputtering from the upper atomic layers of the aluminium surface creates inhomogeneous morphology which triggers the increase the charge density locally. In this study we carried out a comparative study on controlling and modification the thickness and morphology of the oxide layer on aluminium using three different methods thermal oxidation, plasma assisted oxidation and atomic layer deposition (ALD). High Resolution Transmission Electron Microscopy (HRTEM) and X-ray Photoelectron Spectroscopy (XPS) analysis have been carried out to compare the oxide layers and additionally the emission properties of corresponding layers were tested using a customized vacuum system.

Resume : Room temperature, ultra-low power "pump and probe" systems, based on the production and quantum manipulation of photons in the 350-450 nm "blue/UV" spectral range are currently not easily available. It is important to be able to access this spectral region for a variety of reasons, including: (i) future development of new point-of-care medical devices capable of detection of chemical species which have absorption and emission peaks in this region (e.g. glucose, urea, steroids, cysteines, thiolates, carotenoids, porpyryins); (ii) such systems can be switched on and off up to 100 times faster than conventional emitters (high speed telecommunications); (iii) integrated circuit on-chip optical interconnects could be made more feasible as their dimensions would be much smaller using shorter wavelength blue/UV light; and (iv) current state-of-the-art optical emitters (LEDs/lasers) consume too much power. It is important that the power consumption of these blue/UV optical emitters will be 2 to 3 orders of magnitude lower than current conventional laser systems. This can be achieved if one uses a lasing mechanism based on the interaction of photons and electronically bound electron-hole pairs, known as excitons, confined within an optical microcavity. These confined quasiparticles, known as “polaritons” behave like electrons or holes with an effective mass approximately 1/10,000 that of an electron at rest. We will discuss recent advances in the use of copper halide (CuHa) nanosystems (e.g. based on CuCl or CuBr), which can outperform (strongest light matter coupling possible, room temperature quantum entanglement operation) competitor materials such as III-Vs, III-Nitrides, or ZnO. We will discuss the potential for superior operation using copper halide semiconductors since they possess much higher excitonic binding energies – the higher this energy is the more likely that room temperature operation is stable and continuous. Furthermore, exciton complexes, known as biexcitons, can also exist in these materials and the higher the biexcitonic binding energy, the more likely it is that the material can exhibit quantum entanglement effects, which are essential components of future photonic quantum information and communication (QIPC) technologies. The key to making a practical device is to electrically connect to the active polaritonic material inside a microcavity. In order to deliver such a functional blue/UV polaritonic device, based on the CuHa materials system, a number of significant hurdles need to be overcome. Chief among these are the growth of high quality doped active CuHa nanolayers (n-CuCl; p-CuCl; n-CuBr; p-CuBr), ohmic electrical contacts to CuHa layers, microcavity confinement for polaritons, and encapsulation to maintain long term device operation. We will report on recent advances in achieving high quality doped CuHa layers, ohmic contacts thereto, and encapsulation for device operation lasting many months. The way is now clear for the development of microcavity confinement polaritonic devices, and we will discuss the potential for future developments, including the use of Atomic Layer Deposition and related technologies for room temperature device operation.

Resume : Zinc blende-structure copper (I) chloride is a wide, direct bandgap semiconductor with the potential for applications in UV optoelectronics. We report on the structural, optical and photoluminescent properties of CuCl thin films deposited by atomic layer deposition. The CuCl films were deposited at a reaction temperature of 125 °C from [bis(trimethylsilyl)acetylene] (hexafluoroacetylacetonato)copper(I) and pyridine hydrochloride precursors with pulsing times 2 and 6 s with corresponding purging times 4 and 6 s respectively. The CuCl growth was deposited on various substrates: amorphous soda-lime glass, amorphous quartz glass, crystalline silicon and crystalline sapphire of different orientations. The deposited coatings at 100, 200, 500 and 1000 ALD cycles were studied by XPS, XRD, AFM, optical reflectance and photoluminescence. We also investigated the effectiveness of a thin capping layer of aluminium oxide against degradation of the CuCl by atmospheric. The presence of CuCl was confirmed by the x-ray diffraction and photoluminescence measurement which showed a strong signal at approx. 3.25 eV characteristic of the excitonic emission. The presence of crystalline CuCl was strongly influenced by the substrate and the best crystallinity was found on quartz glass, whereas silicon wafers showed no evidence of CuCl crystals in the deposited films. Moreover, we also showed that quick optical reflectance measurement can be used for fast and reliable detection of the presence of CuCl crystals.

Resume : In organic electronics and opto-electronics, alumina layers play a major role as insulating material (gate dielectric), passivation layer or encapsulation layer (gas permeation barrier). Atomic layer deposition (ALD) is known for growing amorphous alumina with high density and high electrical quality, but the deposition conditions usually require either a temperature above 100°C or highly oxidative condition (oxygen plasma or ozone) to obtain a reasonable deposition rate and high material quality. A method for producing high quality alumina below 60°C using low oxidative conditions would be highly welcome for the highly sensitive materials used in organic electronics. We demonstrate a new thermal ALD method for growing alumina from room temperature to 100°C, while keeping a single ALD loop below 1 minute. In these conditions, the films show physical properties very close to alumina grown above 100°C. The films are amorphous, according to X-ray diffraction analysis. Thickness, growth rate and density of the deposited films were measured by profilometer, ellipsometer, scanning electron microscopy and quartz crystal microbalance, showing a high quality film with a high density above 3 g/cm3. The electrical properties were investigated in a capacitor geometry, demonstrating a dielectric constant of 7.7 ± 0.4. The helium transmission rate, below 10-3 g/m2/day, reveals the high gas barrier performances. At last, the refractive index of 1.58 at 500 nm and visible light transmission as high as 90% were measured using ellipsometer and UV-VIS-NIR spectrophotometry. High-resolution X-ray photoelectron spectroscopy was used in order to better understand the oxidation states and coordination of the elements.

Resume : In the last years, the study of structural color obtained from the interaction of light with periodic nanostructures has generated immense interest, as a result of some colors found in nature are based on this interaction. This phenomenon can be applied in relevant scientific areas, such as: optic; photonic; magnetic; sensor; and biologic. High-ordered anodic aluminum oxide (AAO) templates are used to different applications and are one of the most studied periodic nanostructures. On one side, AAO films were fabricated by two step anodization process and the optical properties of these films were analyzed. The morphological parameters of the AAO films were adjusted in order to study the effect of these parameters on the UV-Vis reflectance properties of these films. These parameters are the thickness, pore diameter, interpore distance, porosity, pore arrangement regularity, and anodization electrolyte. The reflectance was found to depend on the thickness of the AAO films, on the interpore distance, and a strong dependence of the reflectance on the anodization electrolyte was found in the UV region. A statistical study was made to obtain a relation between the maximum reflectance and the morphological parameters of the AAO films (thickness and interpore distance) [1]. On the other side, metal-anodic aluminum oxide (AAO)-Al nanostructures were obtained by two steps, chromium thin films were deposited using sputtering system and AAO films were fabricated using a two-step anodization process. The effective refractive index of AAO-Al films as function thickness, electrolyte, pore diameter, interpore distance and porosity (see Figure 1) was calculated from the UV-Vis reflectance. The aim of this work is to study the dependence of morphological parameters on the effective refractive index of AAO films [2]. References [1] Manzano, C.V., J.P. Best, J.J. Schwiedrzik, A. Cantarero, J. Michler, L. Philippe. Journal of Materials Chemistry C, 2016. 4(32): p. 7658-7666. [2] C.V. Manzano, D. Ramos, L. Pethö, G Bürki, J. Michler, L. Philippe. Journal of the Physical Chemistry C. The Journal of Physical Chemistry C, 2018, 122 (1), pp 957–963.

Resume : Mitigating ecological and environmental concerns, Ultra Violet (UV) photodetector device technologies have shown extensive applications in flame detection, secure space-to-space communication and ozone layer monitoring. Gallium Nitride (GaN) wide bandgap semiconductor material remains one of the most promising candidate for this device technology. However, GaN faces the issue of localized surface states which causes large leakage current in the reverse bias at the metal semiconductor interface, thereby degrading the device performance and reliability. In this work, we have demonstrated the use of Self-Assembled Monolayer (SAM) of organic molecules to modify the surface electrical properties of GaN. SAM of differently functionalized Tetra Phenyl Porphyrin (TPP) organic molecules were chemisorbed via native oxide onto the GaN surface, which was confirmed using XPS technique. AFM and KPFM surface characterizations revealed that this surface modification did not affect the surface roughness, but it reduced the surface potential of GaN by ~350 mV. Furthermore, it was observed that the reverse bias leakage current of Ni Schottky barrier diode decreased by 2 to 3 orders of magnitude. Consequently, this convenient method of surface passivation has also proved to be fruitful for UV photodetection. Significant enhancement in photoresponsivity from 5.5 A/W to 29.7 A/W and photodetector current ratio (PDCR) from 237 to 1.5×107 has been observed when these molecularly modified GaN samples were exposed to a broad source of UV light of 250 nm wavelength, in comparison to bare GaN samples. Such improved electrical and UV photodetector device properties post surface modification may be useful for better device functioning.

Resume : Ferroelectric polymers attract attention as they can be easily coated at lower temperatures locally on p/n doped semiconductor surfaces as dielectric layers in integrated circuits. Thickness control and film conformality in polymeric multilayer structures are required for full integration of the ferroelectric polymers to the modern integrated devices. One of the main obstacles preventing such systems is their low dielectric constants. A feasible method to increase the dielectric constants in ferroelectric multilayer systems would be depositing layers with different Curie temperatures. For applications requiring high dielectric constants, Curie temperatures around room temperature are desirable. We use Initiated Chemical Vapor Deposition (iCVD) method to design multilayer poly [(vinylidenefluoride-co-trifluoroethylene] [P(VDF-TrFE)] thin films. We tailor the thickness of the layers and control the composition in a way that affects the Curie temperature. The electrostatic interactions and coupling between the layers affect the electrical properties of the structure. Hence, we report the frequency dependence of dielectric constant, loss tangent (δ), imaginary electric modulus, and conductivity of thin films at room temperature and discuss the change in dielectric constant and dielectric loss at moderately low and high frequencies as a sign of relaxation in ferroelectric phase.

Resume : The ISOBIO project will develop a new approach to insulating materials through the novel combination of existing bio-derived aggregates with low embodied carbon and with innovative binders to produce durable composite construction materials. These novel composites will target 50% lower embodied energy and CO2 at component level and 20% better insulation properties than conventional material. The project will also seek to demonstrate a reduction of at least 15% in total costs and 5% total energy spent over the lifetime of a building. ISOBIO started by identifying promising organic materials that could be used as insulation. Many of these are classified as waste or by-products of processes like food production. Finely chopped bio-materials such as hemp and straw are treated with hygrothermal resins and nano-particles that make them robust, breathable, moisture resistant, and fire retardant. The bio-aggregates are typically the result of combining organic and inorganic materials; the organic material may have natural insulating properties, for example, while the inorganic material may make the resulting bio-aggregate more robust. Combing organic materials with inorganic materials is not always easy, however. Hemp, for instance, is being combined with lime mortar but the two materials have a degree of chemical incompatibility which could result in a reduction in the strength of the composite material. To overcome this challenge, ISOBIO’s researchers are using nano-technology to increase the interfacial strength between the two materials, giving the resulting composite material improved mechanical and structural properties. The new materials not only improve upon the performance of conventional materials, they also offer new features. Hemp shiv, which is the core of the hemp stalk, for example, has a porous structure that provides moisture buffering to maintain humidity at a more constant level. While the new composite materials may provide more comfort, they need to be at least as robust as conventional materials. To make the hemp-based bio-aggregate water repellent, for example, ISOBIO’s researchers are applying hydrophobic treatments to it. The result is that water vapour can travel in and out of the material but liquid water cannot penetrate it. ISOBIO is also making sure that its products can be compared with conventional ones by quantifying the energy efficiency of conventional materials. As part of its life cycle analysis, the project is analysing over 100 existing materials. Despite these efforts, perception and lack of awareness remain major obstacles to adoption. Despite these challenges, the market for ISOBIO’s composite materials is promising. On the supply side, sourcing local organic materials helps reduce transportation costs, while using waste or by-products as inputs helps control the cost of the final product. On the demand side, demographic trends are leading to a shortage of housing, and especially affordable housing. Increasing the availability of new and affordable housing will require novel construction methods and designs that allow more rapid construction. TWI is exploring the development of novel inorganic-organic hybrid nano-materials, to be applied as a surface treatment onto bio-based aggregates. These nanoparticles are synthesised by sol-gel processing and then functionalised with silanes to impart multifunctionality e.g. hydrophobicity, fire resistance and chemical bonding between the silica nanoparticles and the bio-based aggregates. This talk will illustrate the approach taken by TWI to design the functionalised silica nanoparticles by using a material-by-design approach. The formulation and synthesise process will be presented together with the challenges addressed by those hybrid nano-materials. The results obtained with regards to the water repellence and fire resistance will be displayed together with preliminary public results of the ISOBIO project. (This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 641927).

Resume : Particulate matter (PM) pollution has caused a rising impact on public health, production efficiency, and even underlay deteriorated climate and ecosystems in the recent decades. Many efforts have focused on development of high effective filters to eliminate the haze particles in the air. However, current high-efficiency filters know as HEPA filters, electrospun two-dimensional nanofibrous filters do not remove particles with sizes less than 1.0 µm efficiently. More worse, these filters always face an awkward question, efficiency and pressure drop synchronize increase or decrease. To address the aforementioned issues, three-dimensional nanofibrous controllable macrostructures of Fe3+ crosslinked polydopamine (PDA)@PAN (Fe3+/PDA@PAN) filters with high porosity, low density, large specific surface area, mechanically robust, high efficiency but low pressure drop for PM 0.1 were successfully fabricated via electrospinning, PDA coating, Fe3+ crosslinking and freeze-drying process. Morphology characterization and compression test shown that both multiple hydrogen bonding provided by PDA coating and Fe3+-PDA coordination bonding can effectively induce the formation inter-fiber junctions, which befits to construct more robust 3D nanofibrous filters and helps to stabilize the nanoporous fibrous structure in air filtration applications. Fe3+ is demonstrated to be a powerful cross-linking agent and surface chemical modifier. First, it can not only enhance mechanical performance, leading to large pores with honeycomb-like morphology, and thus reducing the pressure drop and protect the samples without damage under high wind speed. Second, Fe3+ offers the electrostatic interaction between haze particles and the filter surface, which benefits adsorption of haze particles. The optimized Fe3+/PDA@PAN filters were further verified by air filtration test, which is conducted by simulated model haze conditions. Results indicated that Fe3+/PDA@PAN filters displayed higher filtration efficiency for PM 0.1 as well as similar pressure drops in contrast with commercial HEPA filters.

Resume : Self cleaning surfaces have been a subject of major research due to their myriad of applications in industrial as well as household products. Till recently the self-cleaning surfaces have been fabricated imitating the lotus leaf effect, i.e. the structural superhydrophobicity. However due to their major limitations against low surface tension liquids, low temperature humid conditions, and mechanical wear and tear, they served a halfway solution as self-cleaning surfaces. A novel solution that circumvents these limitations was recently proposed by a research group in 2011. The concept of such surfaces is inspired by an insect eating carnivores plant called pitcher plant (Nepenthis Alata), which relies on a stable lubricating liquid film to exhibit phenomenal slipperiness to make the insects coming in contact with it to slip further inside it, and are hence called slippery surfaces. Although these slippery surfaces have been shown to perform robustly as anti-icing, self-cleaning, anti-frost, anti-bio-fouling surfaces, their behaviour when subjected to repeated high temperature is not well understood yet. The current endeavour addresses this aspect. We have fabricated copper based slippery surfaces by imparting roughness through a chemical etching procedure, thereby hydrophobising the metallic surface by silanizing and finally coating Silicone oil on it. The surfaces have been characterized for their wettability at each stage of its fabrication. Thermal fatigue of these surfaces was examined by observing the slipperiness (the contact angle hysteresis and the sliding angle) after each thermal cycle (heating to 200°C and cooling to room temperature), for surfaces with three different viscosity silicone oils. We find that the slipperiness at first increases with more number of thermal cycles, reaches a peak and then decreases till the surface becomes sticky unlike any metallic surface. This critical number of thermal cycle increases with the increasing viscosity of the lubricating liquid. We believe that this finding would help in selecting the viscosity of the lubricating oil for the temperature and duration, the surface is intended to be subjected to during its functionality. References 1. Wong, T.-S. et al. Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity. Nature 477, 443–7 (2011). 2. Pengfei Zhang, Huawei Chen, Liwen Zhang, Yi Zhang, D. Z. and L. J. Stable slippery liquid-infused anti-wetting surface at high temperatures. J. Mater. Chem. A 4, 12212–12220 (2016). 3. Joanny, J. F. & de Gennes, P. G. A model for contact angle hysteresis. J. Chem. Phys. 81, 552–562 (1984). 4. Kim, P. et al. Liquid-infused nanostructured surfaces with extreme anti-ice and anti-frost performance. ACS Nano 6, 6569–6577 (2012).

Resume : Offshore pipelines transport the produced hydrocarbon from the upstream production well to the downstream hydrocarbon separation facilities. Although offshore oil and gas pipelines are the safest way of transporting the hydrocarbon as evidenced by significant low failure rates in contrast with highway transportation, railroad, and ships, yet, failures do occur and often with catastrophic results especially to the marine ecology and its environment. There are several origins of pipeline failures, but corrosion is considered to be the main one. Coatings are always used to control external corrosion of pipelines, in combination with impressed cathodic protection. However, development of new coatings has always been an on-going process. A new class of anti-corrosive coatings is based on conducting polymer / graphene-based composites. In this study, we synthesize polyaniline (PANI)/graphene oxide (GO) composite coatings for protection of carbon steel immersed in seawater (NaCl 3.5 wt.%). We investigate the PANI coating with different loading of graphene oxide. The PANI/GO coatings were electrochemically synthesized using a cyclic voltammetry technique. Electrochemical impedance spectroscopy (EIS), linear polarisation resistance (LPR), and Tafel polarisation are used to evaluate the corrosion protection of the coating. The topographical, chemical and structural characterization of the coatings and the steel substrate is done by Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and FTIR-microscopy. Our results indicate that the inclusion of graphene into the PANI layer enhanced the barrier properties of the PANI coatings, and consequently improved the coating’s anti-corrosion properties.