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Titania Films (titania + film)
Selected AbstractsBiomimetically Controlled Formation of Nanotextured Silica/Titania Films on Arbitrary Substrates and Their Tunable Surface FunctionADVANCED MATERIALS, Issue 37 2009Ren-Hua Jin Substrates with arbitrary shapes covered by a linear polyethyleneimine layer can effectively afford complexly nanotextured silica/titania thin films on their surfaces when the substrates are dipped into the source solutions at room temperature. The nanotextured thin films can be turned into superhydrophobic surfaces after they are treated with alkylsilane. [source] Enhanced Ability of Nanostructured Titania Film to Assist Photodegradation of Rhodamine B in Water Through Natural AgingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2007Jin-Ming Wu Gradually but significantly improved abilities of titania films with various nanofeatures and crystal structures to assist photodegradation of trace rhodamine B in water were observed when the films were subjected to natural aging. The so-called natural aging behavior can be attributed to the gradual increase in the surface hydroxyl groups that are beneficial to the photocatalytic reaction. [source] Infiltrating Semiconducting Polymers into Self-Assembled Mesoporous Titania Films for Photovoltaic Applications,ADVANCED FUNCTIONAL MATERIALS, Issue 4 2003K.M. Coakley Abstract Interpenetrating networks of organic and inorganic semiconductors are attractive for photovoltaic cells because electron transfer between the two semiconductors splits excitons. In this paper we show that films of titania with a uniform distribution of pore sizes can be made using a block copolymer as a structure-directing agent, and that 33,% of the total volume of the film can be filled with a semiconducting polymer. [source] A 4,% Efficient Dye-Sensitized Solar Cell Fabricated from Cathodically Electrosynthesized Composite Titania Films,ADVANCED MATERIALS, Issue 21 2003J. Yamamoto Cathodically electrosynthesized TiO2 films (see Figure) containing occluded Degussa P-25 titania particles can yield short-circuit current densities as high as 10.5 mA,cm,2, an open-circuit photovoltage of 690 mV, a fill factor of 57.3,%, and a photovoltaic efficiency of 4.13,% under simulated air mass 1.5 (100 mW,cm,2) sunlight in a dye-sensitized solar cell device. [source] Orientation and Phase Relationships between Titania Films and Polycrystalline BaTiO3 Substrates as Determined by Electron Backscatter Diffraction MappingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2010Nina V. Burbure Titania films have been grown on polycrystalline BaTiO3 (BTO) substrates at 700°C by pulsed laser deposition. Electron backscatter diffraction (EBSD) was used to determine grain orientations in the substrate before growth, and the phase and orientation of the supported films after growth. All BaTiO3 grains within 26° of (001) were covered by anatase films with an orientation relationship of (001)Anatase||(001)BTO and [100]Anatase||[100]BTO. Rutile with a variety of orientations grew on BaTiO3 grains with orientations closer to (110) and (111). EBSD mapping provides an efficient means for determining phase and orientation relationships of films over all orientation parameters. [source] Influence of Dipolar Fields on the Photochemical Reactivity of Thin Titania Films on BaTiO3 SubstratesJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2006Nina V. Burbure The photochemical properties of TiO2 films supported on BaTiO3 were investigated to test the hypothesis that dipolar fields from a ferroelectric substrate would affect the reactivity of the supported film. Photochemical reaction products were formed on the TiO2 surface in patterns that correspond to the underlying domain structure of BaTiO3. As the film thickness increases from 10 to 100 nm, the titania more effectively screens the ferroelectric field, and the pattern of reaction products is obscured. It is concluded that dipolar fields from the ferroelectric substrate influence charge carrier transport in the film and spatially localize the reaction products. [source] Fine Patterning of Hybrid Titania Films by Ultraviolet IrradiationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2003Hiyoro Segawa Photosensitive hybrid titania films have been prepared from titanium butoxide modified with ,-diketone and methacrylic acid. When this film is exposed to UV light, the ,-diketonato chelate from the alkoxide and ,-diketone is dissociated, and the unsaturated hydrocarbon of methacrylic acid is polymerized. These structural changes in the gel film have led to a difference between the solubility of irradiated and unirradiated parts in the film; therefore, a fine patternable hybrid titania film has been fabricated. [source] Tungsten Oxide and Tungsten Oxide-Titania Thin Films Prepared by Aerosol-Assisted Deposition , Use of Preformed Solid NanoparticlesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2007Uzma Qureshi Abstract Aerosol-assisted deposition (AAD) was used to deposit films of WO3 from a suspension of solid nanoparticulate WO3 in toluene. Titania films were deposited by the aerosol-assisted chemical vapour deposition of [Ti(OiPr)4] in the presence of WO3 nanoparticles. The WO3 and TiO2 films exhibited photoactivity and photoinduced superhydrophilicity, further the titania films showed very unusual highly crenulated microstructures. These microstructures could not be obtained by sol-gel, atmospheric pressure chemical vapour deposition or evaporation routes. Furthermore, the microstructures could not be obtained from [Ti(OiPr)4] in the absence of nanoparticulate WO3. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Orientation and Phase Relationships between Titania Films and Polycrystalline BaTiO3 Substrates as Determined by Electron Backscatter Diffraction MappingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2010Nina V. Burbure Titania films have been grown on polycrystalline BaTiO3 (BTO) substrates at 700°C by pulsed laser deposition. Electron backscatter diffraction (EBSD) was used to determine grain orientations in the substrate before growth, and the phase and orientation of the supported films after growth. All BaTiO3 grains within 26° of (001) were covered by anatase films with an orientation relationship of (001)Anatase||(001)BTO and [100]Anatase||[100]BTO. Rutile with a variety of orientations grew on BaTiO3 grains with orientations closer to (110) and (111). EBSD mapping provides an efficient means for determining phase and orientation relationships of films over all orientation parameters. [source] Fine Patterning of Hybrid Titania Films by Ultraviolet IrradiationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2003Hiyoro Segawa Photosensitive hybrid titania films have been prepared from titanium butoxide modified with ,-diketone and methacrylic acid. When this film is exposed to UV light, the ,-diketonato chelate from the alkoxide and ,-diketone is dissociated, and the unsaturated hydrocarbon of methacrylic acid is polymerized. These structural changes in the gel film have led to a difference between the solubility of irradiated and unirradiated parts in the film; therefore, a fine patternable hybrid titania film has been fabricated. [source] Tungsten Oxide and Tungsten Oxide-Titania Thin Films Prepared by Aerosol-Assisted Deposition , Use of Preformed Solid NanoparticlesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 10 2007Uzma Qureshi Abstract Aerosol-assisted deposition (AAD) was used to deposit films of WO3 from a suspension of solid nanoparticulate WO3 in toluene. Titania films were deposited by the aerosol-assisted chemical vapour deposition of [Ti(OiPr)4] in the presence of WO3 nanoparticles. The WO3 and TiO2 films exhibited photoactivity and photoinduced superhydrophilicity, further the titania films showed very unusual highly crenulated microstructures. These microstructures could not be obtained by sol-gel, atmospheric pressure chemical vapour deposition or evaporation routes. Furthermore, the microstructures could not be obtained from [Ti(OiPr)4] in the absence of nanoparticulate WO3. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Nanostructured Titanium Oxynitride Porous Thin Films as Efficient Visible-Active Photocatalysts,ADVANCED FUNCTIONAL MATERIALS, Issue 16 2007E. Martínez-Ferrero Abstract Nanocrystalline mesoporous N-doped titania films have been prepared for the first time. The introduction of nitrogen into the anatase structure starts at 500,°C, with N bonding to titanium via oxygen substitution. Increasing the treatment temperature leads to the formation of TiN (TiN1,xOx) and N-doped rutile showing mixed-valence Ti states. Microstructural characterization shows that the ordered mesoporosity is maintained until 700,°C, where TiN (TiN1,xOx) begins to form. Optical characterization shows that the discrete introduction of N is able to shift the titania absorption edge. The photocatalytic tests give the best results under visible light excitation for the film nitrided at 500,°C. At this temperature the concentration of nitrogen in the structure is optimal since oxygen vacancies are still not important enough to promote the recombination of the photogenerated electrons and holes. [source] Electrodeposition of Titania Thin Films on Metallic Surface for High- k Dielectric ApplicationsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 3 2010Biplab K. Roy Current microelectronics devices based on flexible as well as rigid substrates demand high dielectric constant (k) films to be grown on conductive substrate from a low-cost, low-temperature deposition technique. In this study, we produced high- k titania (TiO2) films through an affordable electrodeposition protocol from the electrochemical bath maintained at about 0°C. The deposition occurs through a rapid hydrolysis mechanism of titanium containing ions in the precursor solution aided by electrochemically generated hydroxyl ions formed near the cathode surface (copper (Cu) substrate). Upon attaining a sufficient supersaturation level, such hydrolyzed species precipitate to form a titania thin film on the cathode surface. While depositing from a highly acidic precursor solution, Cu substrate was protected by a cathodic potential (,3 to ,5 V against the counter electrode). The resultant titania films show nanoparticulate structures evolved from nucleation and growth events of the in situ precipitated particles. Much higher deposition rate (about 1 ,m/min) was observed compared with that of typical chemical bath deposition. The resultant films with a thickness of 1500 nm grown on Cu exhibit very high dielectric properties (e.g., k,30, capacitance density >110 nF/in.2 at 100 kHz) and moderate breakdown voltage (VB) (,17.5 V). These properties indicate the potential of electrodeposited titania films to be used as a small-area thin-film capacitor for miniaturized electronic devices. [source] Enhanced Ability of Nanostructured Titania Film to Assist Photodegradation of Rhodamine B in Water Through Natural AgingJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2007Jin-Ming Wu Gradually but significantly improved abilities of titania films with various nanofeatures and crystal structures to assist photodegradation of trace rhodamine B in water were observed when the films were subjected to natural aging. The so-called natural aging behavior can be attributed to the gradual increase in the surface hydroxyl groups that are beneficial to the photocatalytic reaction. [source] Fine Patterning of Hybrid Titania Films by Ultraviolet IrradiationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2003Hiyoro Segawa Photosensitive hybrid titania films have been prepared from titanium butoxide modified with ,-diketone and methacrylic acid. When this film is exposed to UV light, the ,-diketonato chelate from the alkoxide and ,-diketone is dissociated, and the unsaturated hydrocarbon of methacrylic acid is polymerized. These structural changes in the gel film have led to a difference between the solubility of irradiated and unirradiated parts in the film; therefore, a fine patternable hybrid titania film has been fabricated. [source] Low Temperature Growth of Photoactive Titania by Atmospheric Pressure PlasmaPLASMA PROCESSES AND POLYMERS, Issue 9 2009John L. Hodgkinson Abstract Atmospheric pressure glow discharge plasma CVD was used to deposit thin films of titania at 200,°C using two different precursors. The resulting films were characterised using techniques including XPS, RBS and XRD. It was established that annealing at temperatures as low as 275,°C produced crystalline films that were photocatalytically active. When annealed at 300,°C the photoactivity was greater than that of commercially available "self-cleaning" titania films. The effects of the different precursors, annealing times and temperatures on the crystallinity and photoactivity are discussed. [source] Density Investigation by X-ray Reflectivity for Thin Films Synthesized Using Atmospheric CVD,CHEMICAL VAPOR DEPOSITION, Issue 9-10 2008Shinichi Kishimoto Abstract The density of hafnia and titania films is investigated by an X-ray reflectivity (XRR) analysis using an X-ray diffractometer equipped with a relatively low power X-ray source. Several films are prepared using a CVD technique operated under atmospheric pressure. The XRR profile of the hafnia films is obtained, and fitted with the assumption of the existence of an HfSiO intermediate layer on the Si substrate with a SiO2 layer. The density of the hafnia films is lower than that of the bulk crystal. On the other hand, the XRR profile of the titania films on the glass substrate can be fitted using a seven-lamella model. The film density of titania is also lower than that of the bulk crystal. XRR analysis may become a powerful weapon to determine not only the structure model but also the crystallinity of each layer. [source] The Influence of Charge Transport and Recombination on the Performance of Dye-Sensitized Solar CellsCHEMPHYSCHEM, Issue 1 2009Mingkui Wang Dr. Abstract Electrochemical impedance spectroscopy (EIS) and transient voltage decay measurements are applied to compare the performance of dye sensitized solar cells (DSCs) using organic electrolytes, ionic liquids and organic-hole conductors as hole transport materials (HTM). Nano-crystalline titania films sensitized by the same heteroleptic ruthenium complex NaRu(4-carboxylic acid-4,-carboxylate) (4,4,-dinonyl-2,2,-bipyridyl)(NCS)2,, coded Z-907Na are employed as working electrodes. The influence of the nature of the HTM on the photovoltaic figures of merit, that is, the open circuit voltage, short circuit photocurrent and fill factor is evaluated. In order to derive the electron lifetime, as well as the electron diffusion coefficient and charge collection efficiency, EIS measurements are performed in the dark and under illumination corresponding to realistic photovoltaic operating conditions of these mesoscopic solar cells. A theoretical model is established to interpret the frequency response off the impedance under open circuit conditions, which is conceptually similar to photovoltage transient decay measurements. Important information on factors that govern the dynamics of electron transport within the nanocrystalline TiO2 film and charge recombination across the dye sensitized heterojunction is obtained. [source] | |||||||||||||