Download or read book Characterization of the Optical Properties of Metalloporphyrins in TiO2 Sol gel Films for Photon Upconversion Applications written by Terri Thunder and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Chromium Doped TiO2 Sputtered Thin Films written by Anouar Hajjaji and published by Springer. This book was released on 2014-12-24 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents co-sputtered processes ways to produce chrome doped TiO2 thin films onto various substrates such as quartz, silicon and porous silicon. Emphasis is given on the link between the experimental preparation and physical characterization in terms of Cr content. Moreover, the structural, optical and optoelectronic investigations are emphasized throughout. The book explores the potencial applications of devices based on Cr doped TiO2 thin films as gas sensors and in photocatalysis and in the photovoltaic industry. Also, this book provides extensive leads into research literature, and each chapter contains details which aim to develop awareness of the subject and the methods used. The content presented here will be useful for graduate students as well as researchers in materials science, physics, chemistry and engineering.

Download or read book Uniformity and Optical Properties of Titanium Dioxide Film by Sol Gel Technique written by and published by . This book was released on 2014 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Sol gel Thin Films of TiO2 PbO TiO2 Bi2O3 and TiO2 CeO2 Compositions written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preparation and Characterization of Sol gel Derived Metal Oxide Thin Films and Powders for Coatings and Catalysts written by Per A. Askeland and published by . This book was released on 1997 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synthesis and Characterization of Sol gel Derived Tantalum Oxide Tantalum Nitride and Nickel alumina Thin Films written by Gerald Thomas Kraus and published by . This book was released on 1997 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of TiO2 Thin Films Prepared by Sol gel Processing written by Özlem Kaya and published by . This book was released on 2002 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optical Properties of Doped Tin Dioxide Thin Films Prepared Using Sol Gel Dip Coating Method written by Shahida Hanum Kamarullah and published by . This book was released on 2008 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Photocatalytic Activity of Porous Films by In situ Environmental Ellipsometric Analysis written by Ronghua Li and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: TiO2-based materials have been extensively studied as potential material to be used in photocatalysis. In particular crystalline mesoporous thin films exhibit increased photocatalytic activities due to their exceptionally high surface area. However the study and the optimization of the photocatalysis in such porous media is not easy to be done due to the fact that the catalytic process is highly dependent from several environmental and structural parameters. The research activities of this thesis were essentially focused on (i) the fabrication of mesoporous TiO2-based photoactive thin films with tunable composition and nanostructure and (ii) their utilization as platform for fundamental study of the photocatalytic process by ellipsometry. The mesoporous films with tunable nanostructure will be fabricated by coupling sol-gel chemistry and highly controlled liquid deposition techniques. Among modern analytical tools, 2D-GISAXS, ellipsometry and ellipso-porosimetry, SEM-FEG, HR-TEM and WAXS, were used to obtain a large set of relevant information. In the first part, a model TiO2 mesoporous film was analysed by ellipsometry for fundamental investigations of the photocatalytic process kinetics in air as function of the environmental and the organic pollutant. The information obtain by ellipsometry has allowed the proposition of photodegradation mechanisms in the studied conditions. In the second part, composite mesoporous TiO2/SiO2 films with tunable optical properties were fabricated by sol-gel chemistry. A structural study on the films porous network and composition was conducted. In-situ ellispometry was also used to study the photocatalytic activity.

Download or read book Interactions Between Sintering Crystallization and Chemical Development of Sol gel and Colloidal Titanium Dioxide Thin Films written by Joseph Louis Keddie and published by . This book was released on 1993 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Solar Energy Transfer Through Plasmonic Au Nanoparticle doped Sol derived TiO2 Thin Films in Photocatalysis and Photovoltaics written by Andrew Zelinski and published by . This book was released on 2013 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium Dioxide (TiO2) films were elaborated using the Sol-Gel technique and subsequently used to study plasmonic photovoltaic and photocatalytic energy transfer enhancement mechanisms. TiO2 was chosen because of the unique optical and electrical properties it possesses as well as its ease of preparation and operational stability. The properties of sol-elaborated films vary significantly with processing environment and technique, and the sol formula; a systematic investigation of these variables enabled the selection of a consistent technique to produce relatively dense, crack-free TiO2 thin films. Localized Surface Plasmon Resonance (LSPR) energy transfer was investigated by integrating plasmonic Au nanoparticles into multi-layer wide-band gap semiconductor (TiO2) devices, and by doping strongly catalytic TiO2 anodes in a 3-electrode photochemical cell. An instant 3x photocurrent enhancement in the multilayer solar cell device was observed under 650nm light illumination, which suggests the presence of a resonant energy transfer. The focus of this work was to develop a systematic analysis of the actual mechanics of energy transfer responsible for the light-harvesting enhancements seen in previous studies of Au nanoparticle-TiO2 systems under visible illumination15−29. This mechanism remains the subject of debate and models have been proposed by various researchers. A method is developed here to pinpoint the most influential of the proposed mechanisms.

Download or read book Optical Properties of Sensitized Tin Dioxide Thin Film Prepared by Using Sol gel Spin Coating Method written by Shahida Hanum Kamarullah and published by . This book was released on 2010 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fabrication and Characterisation of Sol gel Based Barium Gadolinium Titanate Thin Films for Photovoltaics written by Yen Chin Teh and published by . This book was released on 2018 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this researchare summarized as below ; to fabricate Barium Gadolinium Titanate (BGT) thin films with perovskite structure using the sol-gel method ; to investigate the basic properties of the BGT film including structural, surface morphology, optical response and electric properties of the films ; to study the feasibility of the BGT film for photovoltaic application.

Download or read book Characterization of TiO2 Coated Particles Prepared by Sol gel Method written by Hiromasa Okada and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of Photocatalytic Processes at Nanoporous TiO2 Film Electrodes by Photoelectrochemical Techniques and Development of a Novel Methodology for Rapid Determination of Chemical Oxygen Demand written by Dianlu Jiang and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this work, a series of simple, rapid and effective photoelectrochemical methodologies have been developed and successfully applied to the study of kinetic and thermodynamic characteristics of photocatalytic oxidation processes at TiO2 nanoparticulate films. As an application of the systematic studies of photocatalytic processes by photoelectrochemical techniques, a rapid, direct, absolute, environmental-friendly and accurate COD analysis method was successfully developed. In this work, the TiO2 nanoparticles colloid was prepared by the sol-gel method. The TiO2 nanoparticles were immobilized onto ITO conducting glass slides by dip-coating method. Thermal treatment was carried out to obtain nanoporous TiO2 films of different structures. At low calcination temperature (below 600 degrees C), nanoporous TiO2 films of pure anatase phase were prepared. At high calcination temperature (above 600 degrees C), nanoporous TiO2 films of mixed anatase and rutile phases were obtained. At these film electrodes, the work was carried out. By employing steady state photocurrent method and choosing phthalic acid as the model compound, the photocatalytic activity of the TiO2 nanoporous films calcined at various temperatures and for different lengths of time was evaluated. It was found that the films with mixed anatase and rutile phases calcined at high temperature exhibited high photocatalytic activity. Based on semiconductor band theory, a model was proposed, which explained well this finding. By employing linear sweep voltammetry (under illumination) and choosing glucose (an effective photohole scavenger) as a model compound, the characteristics of the photocatalytic processes at nanoparticulate semiconductor electrodes were investigated. Characteristics of the nanoporous semiconductor electrodes markedly different from bulk semiconductor electrodes were observed. That is, within a large range of electrode potentials above the flat band potential the electrodes behaved as a pure resistance instead of exhibiting variable resistance expected for bulk semiconductor electrodes. The magnitude of the resistance was dependent on the properties of the electrodes and the maximum photocatalytic oxidation rate at TiO2 surface determined by the light intensity and substrate concentration. A model was proposed, which explained well the special characteristics of particulate semiconductor electrodes (nanoporous semiconductor electrodes). This is the first clear description of the overall photocatalytic process at nanoparticulate semiconductor electrodes. The investigation set a theoretical foundation for employing photoelectrochemical techniques to study photocatalytic processes. By using the transient technique (illumination step method analogous to potential step method in conventional electrochemistry), the adsorption of a number of strong adsorbates on both low temperature and high temperature calcined TiO2 nanoporous films was investigated. Similar adsorption characteristics for different adsorbates on different films were observed. In all the cases, three different surface bound complexes were identified, which was attributed to the heterogeneity of TiO2 surface. The photocatalytic degradation kinetics of the pre-adsorbed organic compounds of different chemical nature was also studied by processing the photocurrent-time profiles. Two different photocatalytic processes, exhibiting different rate characteristics, were observed. This was, again, attributed to the heterogeneity of the TiO2 surface corresponding to heterogeneous adsorption characteristics. The catalytic first order rate constants of both fast and slow processes were obtained for different organic compounds. It was found that for different adsorbates of different chemical nature the magnitudes of rate constant for the slow kinetic process were very similar, while the magnitudes of rate constant for the fast process were significantly affected by the photohole demand characteristics of different adsorbates. Photohole demand distribution that depends on the size and structure of the adsorbed molecules was believed to be responsible for the difference. By employing steady state photocurrent method, the photocatalytic degradation kinetic characteristics of both strong adsorbates and weak adsorbates of different chemical structures were compared at pure anatase TiO2 nanoporous TiO2 films as well as at anatase/rutile mixed phase TiO2 nanoporous film electrodes. At the former electrodes for all the different organic compounds studied, the photocatalytic reaction rate increased linearly with concentration at low concentrations. Under such conditions, it was demonstrated that the overall photocatalytic process was controlled by diffusion and was independent of the chemical nature of organic compounds. However, the linear concentration range and the maximum photocatalytic reaction rate at high concentrations were significantly dependent on the chemical nature of the substrates. This was explained by the difference in the interaction of different organic compounds with TiO2 surface, the difference in their photohole demand distributions at the TiO2 surface and the difference in their nature of intermediates formed during their photocatalytic mineralization. In contrast, at the latter electrodes for the photocatalytic oxidation of different organic compounds the linear ranges (diffusion control concentration range) and the maximum reaction rates at high concentration were much larger than at the former electrodes and much less dependent on the chemical nature of the organic compounds. The spatial separation of photoelectrons and photoholes (due to the coexistence of rutile phase and anatase phase) and the increase in the lifetime of photoelectrons and photoholes are responsible for the excellent photocatalytic activity of the electrodes. By employing the thin-layer photoelectrochemical technique (analogous to the thin-layer exhaustive electrolytic technique), the photocatalytic oxidation of different organic compounds at the mixed phase TiO2 nanoporous electrodes were investigated in a thin layer photoelectrochemical cell. It was found that the charge derived from exhaustive oxidation agreed well with theoretical charge expected for the mineralisation of a specific organic compound. This finding was true for all the compounds investigated and was also true for mixtures of different organic compounds. The photocatalytic degradation kinetics of different organic compounds of different chemical identities in the thin layer cell was also investigated by the photoelectrochemical method. Two kinetic processes of different decay time constants were identified, which were attributed to the degradation of preadsorbed compounds and the degradation of compounds in solution. For the degradation of compounds in solution, a change in the overall control step from substrate diffusion to heterogeneous surface reaction was observed. For different organic compounds, the variation of the rate constant was determined by the photohole demand rather than by the chemical identities of substrates. The kinetics of the fast kinetic process, on the other hand, was greatly affected by the adsorption properties of the substrates. For the strong adsorbates, the rate was much larger than for weak adsorbates. However, the rate constant of the process was independent of the chemical identities of the substrates and the variation of the constant was also determined by the photohole demand. Based on the principles of exhaustive photoelectrocatalytic degradation of organic matter in a thin layer cell, a novel, rapid, direct, environmental-friendly and absolute COD analysis method was developed. The method was tested on synthetic samples as well as real wastewater samples from a variety of industries. For synthetic samples with given compositions the COD values measured by my method agree very well with theoretical COD value. For real samples and synthetic samples the COD values measured by my method correlated very well with those measured by standard dichromate COD analysis method.

Download or read book written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the First International Workshop on Optical Power Limiting written by Francois Kajzar and published by CRC Press. This book was released on 1999 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: