Download or read book Development of Highly Porous Crystalline Titania Photocatalysts written by Michał Marszewski and published by . This book was released on 2016 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objectives of this dissertation are the design, synthesis, and characterization of titania materials with surface area, porosity, crystallinity and doping tailored toward photocatalytic applications. Ultimately, the research should result in a strategy allowing the synthesis of titania with all these important features. The synthetic methods investigated in this research will include: i) soft-templating, ii) hard-templating, and iii) modified precursor strategy. Soft-templating strategy uses organic templates--either block copolymers or surfactants--that under specific conditions assemble into micelles, and later, these micelles are used to template the desired material around them. The resulting organic-inorganic composite is then calcined in air to remove the organic template and recover the final material with high surface area and large pore volume. This work explores 1) synthesis of titania materials in the presence of polymer templates, and the effects of different synthetic conditions on the structure of the resulting materials. Hard-templating, in contrast to soft-templating, uses inorganic templates. The hard template is introduced during the synthesis to cast its shape onto the fabricated material and removed afterwards, when the material has formed. The final material is an inverse replica of the hard template used, typically with a well-developed mesostructure. This work explores 1) hard templating synthesis of titania materials using silica and alumina, and 2) the effects of the template amount and type. The modified precursor strategy is a novel synthetic method, developed in this research, and designed specifically to achieve titania material with high surface area, large pore volume, high crystallinity, and possibly doping. The modified precursors are prepared by reacting generic titania precursors, such as titanium isopropoxide (TIPO), with organic acids, which results in substitution of some or all alkoxide groups in TIPO structure. The goal is to introduce new, easily carbonizable groups in TIPO structure so that the modified precursor can serve as titania and carbon precursor simultaneously. Subsequently, during carbonization in inert atmosphere, a carbon framework is formed that works as a scaffold, protecting titania during its crystallization. Afterwards, the carbon scaffold is removed by calcination in air. This work explores the modified precursor strategy by 1) preparing titania materials from TIPO modified with different carboxylic acids and 2) investigating the effect of the modifying acid on the properties of the carbon-titania composites and the final titania materials.

Download or read book Development of Novel Titania Based Photocatalysts for Solar H2 Production written by Sy Eun Park and published by . This book was released on 2014 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of a hydrogen (H2) economy hinges on the discovery of simple, low-cost and environmentally friendly technologies for H2 production. Photocatalytic water splitting using sunlight and semiconductor photocatalysts has the potential to deliver an unlimited supply of carbon free H2 gas. Semiconductor photocatalysts such as titania (TiO2) are active for photocatalytic water splitting and/or ethanol photodecomposition under UV light in the presence of certain metal co-catalysts (M). Considerable research effort is now being directed into the development of improved M/TiO2 photocatalysts for H2 production from water and biofuels. This MSc research project targeted the development of novel M/TiO2 (M=Pd, Pt, Au) photocatalysts for H2 production from biofuels (alcohol-water mixtures). This work utilised a range of different TiO2 supports (some we fabricated, others commercially available) and then systematically examined the effect of metal co-catalyst deposition and treatment conditions on the activity of resulting M/TiO2 photocatalysts. The project began with the synthesis of sub-micron sized monodisperse TiO2 colloids by the controlled hydrolysis of titanium (IV) tetraisopropoxide (TTIP) in an acetonitrile:methanol:H2O solvent mixture using dodecylamine (DDA) as the catalyst and structure directing agent. By varying the TTIP:H2O ratio, it was possible to produce batches of monodisperse amorphous TiO2 colloids of different diameter. These colloids readily self-assemble under gravitational sedimentation to give 3D TiO2 colloidal crystals with pseudo photonic band gaps (PBGs) at NIR wavelengths. Calcination of the TiO2 colloids at 500°C or hydrothermal treatment at 160°C in ethanol:H2O solutions, followed by calcination at 500°C, yielded low (~10 m2/g) and high surface area (~70 m2/g) anatase colloidal crystals, respectively. Calcination at 750°C yielded rutile colloidal crystals. The optical properties of the TiO2 colloidal crystals were examined by UV-Vis reflectance measurements, and were consistent with a modified Bragg's Law expression that considered both the refraction and diffraction of electromagnetic radiation in the 3D colloidal crystals. A series of Si1-xTixO2 inverse opal photonic crystals with 3-dimensionally ordered macroporous structures, solid volume fractions between 5-10% and pseudo PBGs at visible wavelengths were then successfully fabricated, using poly (methyl methacrylate) (PMMA) colloidal crystals as sacrificial templates. The structural and optical properties of the Si1- xTixO2 inverse opals (x=0-1) were systematically characterised using SEM, TEM, XRD, UVVis and N2 physisorption. The structural data revealed a progressive transition from amorphous SiO2 to nanocrystalline anatase as the TiO2 content in the Si1-xTixO2 inverse opals increased. The pseudo PBG for Bragg diffraction on fcc (111) planes red-shifted and broadened as the TiO2 content increased, consistent with the fact that anatase (n=2.2-2.3) has a higher refractive index than amorphous SiO2 (n=1.45). The TiO2 colloids, Si1-xTixO2 inverse opals and a commercially available TiO2 (Degussa P25 TiO2) were then functionalised with Pd, Pt or Au nanoparticles to give a series of M/TiO2 photocatalysts. The metal loadings were 0.5-4 wt.%. The activity of all the TiO2 photocatalysts for H2 production from ethanol-water mixtures (80 vol.% and 10 vol.%) under UV excitation increased dramatically after the addition of the noble metal, which is explained by the metal co-catalysts acting as sinks (electron acceptors) for electrons photoexcited in TiO2, thereby preventing electron-hole pair recombination. In TiO2, ethanol serves as a sacrificial hole acceptor (electron donor) and proton source in the reaction. H2 production tests were carried out at UV-fluxes comparable to that of sunlight. Highest rates of H2 production were observed in the M/P25 TiO2 system (1 wt.% Pt/P25 TiO2=56.4 mmol g-1 h-1, 1 wt.% Pd/P25 TiO2=50.4 mmol g-1 h-1, 2 wt.% Au/P25 TiO2=47.2 mmol g-1 h-1) with rates being strongly dependent on the catalyst preparation and pretreatment conditions which influences both co-catalyst particle size and dispersion over the TiO2 support. Lower rates of H2 production were seen in the Au/TiO2 colloid and Au/TiO2 inverse opal systems, which is explained in terms of phase composition of TiO2 present in these samples. Degussa P25 TiO2, which is a mixture of anatase and rutile (85 wt.% anatase; 15 wt.% rutile), is a superior photocatalyst support than pure anatase (of which both the TiO2 colloids and TiO2 inverse opals are composed) on account of the synergistic electron transfer processes that occur at the anatase/rutile interface. On the basis of the results presented, strategies for optimising the activity of M/TiO2 photocatalysts for solar H2 production from biofuels can be developed.

Download or read book Environmentally Benign Photocatalysts written by Masakazu Anpo and published by Springer Science & Business Media. This book was released on 2010-11-10 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few decades, mankind has observed an unprecedented and remarkable growth in industry, resulting in a more prosperous lifestyle for peoples of many countries. In developing countries, however, explosive industrial growth is just now beginning to raise the living standards of the people. Most industries, especially in these developing countries, are still powered by the burning of fossil fuels; con- quently, a lack of clean energy resources has caused environmental pollution on an unprecedented large and global scale. Toxic wastes have been relentlessly released into the air and water leading to serious and devastating environmental and health problems while endangering the planet and life itself with the effects of global warming. To address these urgent environmental issues, new catalytic and photocatalytic processes as well as open-atmospheric systems are presently being developed that can operate at room temperature while being totally clean and ef?cient and thus environmentally harmonious. Essential to technologies harnessing the abundant solar energy that reaches the earth are the highly functional photocatalytic proce- es that can utilize not only UV light, but also visible light.

Download or read book TiO2 Photocatalysis written by Akira Fujishima and published by . This book was released on 1999 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Alternative Approaches in Development of Heterogeneous Titania Based Photocatalyst written by Yolice P. Moreno and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Three alternative approaches for the development of heterogeneous photocatalysts are comparatively evaluated, namely (i) the use of molecular imprinting concept for the development of heterogeneous catalysts employing rhodamine B as template and sol-gel as synthesis route; (ii) the impregnation of TiCl4 on mixed nano- and micro-metric silicas, followed by calcination; (iii) the use of industrial and academic chemical residues as source of potential photocatalyst species impregnated on supports. All tests were carried on with rhodamine B as target molecule. For comparative reasons, photocatalytic tests were carried out with commercial titania (P25). The solids were characterized by nitrogen porosimetry, small-angle X-ray scattering (SAXS), zeta potential (ZP), diffuse reflectance spectroscopy in the ultraviolet region (DRS-UV), diffuse reflectance infrared Fourier transmission spectroscopy (DRIFTS), and Rutherford backscattering spectrometry (RBS). The supported catalysts resulting from silica nanoparticles and residue of the petrochemical industry achieved higher percentage of the dye degradation under ultraviolet (68.0 and 66.8%, respectively) radiation. The industrial waste reached the highest photocatalytic activity under visible (61%) radiation, while the commercial P25 achieved 82.0and 12.3% for ultraviolet and visible radiation, respectively. The textural and structural characteristics of the supported catalyst prepared with fumed silica and petrochemical waste (SiPe), namely the low-energy bandgap (1.8 eV), large surface area (280 m2 g−1), high pore volume (1.9 cm3 g−1), and high zeta potential value (−36.4 mV), may have been responsible for their high activity.

Download or read book Application of Titanium Dioxide Photocatalysis to Construction Materials written by Yoshihiko Ohama and published by Springer Science & Business Media. This book was released on 2011-05-12 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium dioxide photocatalysis is based on the semiconducting nature of its anatase crystal type. Construction materials with titanium photocatalyst show performances of air purification, self-cleaning, water purification, antibacterial action. This book describes principles of titanium dioxide photocatalysis, its applications to cementitious and noncementitious materials, as well as an overview of standardization of testing methods.

Download or read book Environmentally Benign Photocatalysts written by Masakazu Anpo and published by Springer. This book was released on 2016-04-01 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium oxide-based catalysts show promise as a stable, non-toxic photofunctional material. This book covers approaches in the design of titanium oxide-based photocatalysts: sol-gel, precipitation, dip-coating, metal implantation and sputtering deposition.

Download or read book Characterization of Porous Solids VI written by and published by Elsevier. This book was released on 2002-11-14 with total page 809 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains 99 of the papers that were presented at the 6th in the series of Symposia on Characterization of Porous Solids held in Alicante, Spain, May 2002. Written by leading international specialists in the subject, the contributions represent an up-to-date and authoritative account of recent developments around the world in the major methods used to characterize porous solids. The book is a useful work of reference for anyone interested in characterizing porous solids, such as MCM-41 mesoporous materials, pillared clays, etc. Papers on pore structure determination using gas adsorption feature strongly, together with papers on small angle scattering methods, mercury porosimetry, microcalorimetry, scanning probe microscopies, and image analysis.

Download or read book Nanocasting written by An-Hui Lu and published by Royal Society of Chemistry. This book was released on 2010 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructured materials with tailored properties are regarded as a fundamental element in the development of future science and technology. Research is still ongoing into the nanosized construction elements required to create functional solids. The recently developed technique, nanocasting, has great advantage over others in terms of the synthesis of special nanostructured materials by the careful choice of suitable elements and nanoengineering steps. This new book summarizes the recent developments in nanocasting, including the principles of nanocasting, syntheses of novel nanostructured materials, characterization methods, detailed synthetic recipes and further possible development in this area. The book focuses on the synthesis of porous solids from the viewpoint of methodology and introduces the science of nanocasting from fundamental principles to their use in synthesis of various materials. It starts by outlining the principles of nanocasting, requirements to the templates and precursors and the tools needed to probe matter at the nanoscale level. It describes how to synthesize nano structured porous solids with defined characteristics and finally discusses the functionalization and application of porous solids. Special attention is given to new developments in this field and future perspectives. A useful appendix covering the detailed synthetic recipes of various templates including porous silica, porous carbon and colloidal spheres is included which will be invaluable to researchers wanting to follow and reproduce nanocast materials. Topics covered in the book include: * inorganic chemistry * organic chemistry * solution chemistry * sol-gel and interface science * acid-base equilibria * electrochemistry * biochemistry * confined synthesis The book gives readers not only an overview of nanocasting technology, but also sufficient information and knowledge for those wanting to prepare various nanostructured materials without needing to search the available literature.

Download or read book New and Future Developments in Catalysis written by Steven L Suib and published by Newnes. This book was released on 2013-07-13 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: New and Future Developments in Catalysis is a package of seven books that compile the latest ideas concerning alternate and renewable energy sources and the role that catalysis plays in converting new renewable feedstock into biofuels and biochemicals. Both homogeneous and heterogeneous catalysts and catalytic processes will be discussed in a unified and comprehensive approach. There will be extensive cross-referencing within all volumes.The use of catalysts in the nanoscale offers various advantages (increased efficiency and less byproducts), and these are discussed in this volume along with the various catalytic processes using nanoparticles. However, this is not without any risks and the safety aspects and effects on humans and the environment are still unknown. The present data as well as future needs are all part of this volume along with the economics involved. Offers in-depth coverage of all catalytic topics of current interest and outlines future challenges and research areas A clear and visual description of all parameters and conditions, enabling the reader to draw conclusions for a particular case Outlines the catalytic processes applicable to energy generation and design of green processes

Download or read book Heterogeneous Photocatalysis written by Mario J. Muñoz-Batista and published by Springer Nature. This book was released on 2020-07-01 with total page 301 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Current Chemistry Collections presents critical reviews from the journal Topics in Current Chemistry organized in topical volumes. The scope of coverage is all areas of chemical science including the interfaces with related disciplines such as biology, medicine and materials science. The goal of each thematic volume is to give the non-specialist reader, whether in academia or industry, a comprehensive insight into an area where new research is emerging which is of interest to a larger scientific audience. Each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years are presented using selected examples to illustrate the principles discussed. The coverage is not intended to be an exhaustive summary of the field or include large quantities of data, but should rather be conceptual, concentrating on the methodological thinking that will allow the non-specialist reader to understand the information presented. Contributions also offer an outlook on potential future developments in the field. The chapter "Mechanochemical Forces as a Synthetic Tool for Zero and One-Dimensional Titanium Oxide-Based Nano-photocatalysts" is available open access under a CC BY 4.0 License via link.springer.com.

Download or read book Recent Advances in the Science and Technology of Zeolites and Related Materials written by and published by Elsevier. This book was released on 2004-12-18 with total page 1149 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent Advances in the Science and Technology of Zeolites and Related Materials

Download or read book Titanium Dioxide written by Dongfang Yang and published by BoD – Books on Demand. This book was released on 2018-06-27 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium dioxide is currently being used in many industrial products. It provides unique photocatalytic properties for water splitting and purification, bacterial inactivation, and organics degradation. It has also been widely used as the photoanode for dye-sensitized solar cells and coatings for self-cleaning surfaces, biomedical implants, and nanomedicine. This book covers various aspects of titanium dioxide nanomaterials including their unique one-dimensional, two-dimensional, mesoporous, and hierarchical nanostructures and their synthetic methods such as sol-gel, hydrothermal, anodic oxidation, and electrophoretic deposition, as well as its key applications in environmental and energy sectors. Through these 24 chapters written by experts from the international scientific community, readers will have access to a comprehensive overview of the recent research and development findings on the titanium dioxide nanomaterials.

Download or read book Introduction to Photocatalysis written by Yoshio Nosaka and published by Royal Society of Chemistry. This book was released on 2019-03-07 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting the basic science of semiconductor photocatalysis together with the various practical applications, this textbook is ideal for graduate students. It covers fundamental principles and applicable techniques of light, solid state physics, electrochemistry, reaction kinetics, and materials processing. A solid understanding of semiconductor photoelectrochemistry is developed through discussing the basic properties of a representative photocatalytic material, TiO2; the basic science of the light absorption phenomenon and the application to the powder suspension useful for the photocatalytic research; and the electronic state of semiconductors. Following this, the textbook moves on to explore photoelectrochemistry; the mechanism and kinetic analysis of photocatalytic reactions; typical fabrication methods of common photocatalysts and the factors for improving photocatalytic activity; and evaluation methods of photocatalytic activity. The textbook concludes by looking at the future prospects of the applications of photocatalysis. This introductory textbook provides a foundation in photocatalysis to supplement graduate courses in catalysis, environmental science, materials science and chemical engineering.

Download or read book Synthesis Characterization and Applications of Nanomaterials in the Field of Photocatalysis written by Shamaila Sajjad and published by GRIN Verlag. This book was released on 2011-08 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doctoral Thesis / Dissertation from the year 2011 in the subject Chemistry - Materials Chemistry, East China University of Science and Technology (-), language: English, abstract: Considerable effort has been made to design, fabricate, and manipulate nanostructured materials by innovative approaches. The precise control of nanoscale structures will pave the way not only for elucidating unique size/shape dependent physicochemical properties but also for realizing new applications in science and technology. Nanotechnology offers unprecedented opportunities for improving our daily lives and the environment in which we live. This thesis mainly describes recent progress in the design, fabrication, and modification of nanostructured semiconductor materials for environmental applications. The scope of this thesis covers TiO2, Bi2O3 and BiOCl materials, focusing particularly on TiO2-based nanostructures (e.g., pure, doped, coupled, mesoporous, hierarchically porous, and ordered mesoporous TiO2). Mesoporous titania is of particular interest since this class of materials possesses well-defined porosity and large specific surface areas. For photocatalytic degradation of organics, these desirable properties are anticipated to improve the efficiency. So in the first part of work, I have synthesized the mesoporous titania by using poly ethylene glycol as a template in dilute acetic acid aqueous solution by hydrothermal process and investigated the effect of PEG molecular weights and thermal treatment on the resultant structure and photocatalytic activity. When the molecular weights of PEG vary from 600 to 20,000, the particle sizes of mesoporous-TiO2 structure decrease from 15.1 to 13.3 nm and mean pore sizes increase from 6.9-10.6 nm. The activities of these mesoporous-TiO2 photocatalysts prepared by using PEG are evaluated and compared with Degussa P-25 using chloro-phenol as a testing compound. [...]

Download or read book TiO2 Nanoparticles written by Aiguo Wu and published by John Wiley & Sons. This book was released on 2020-06-02 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unique book that summarizes the properties, toxicology, and biomedical applications of TiO2-based nanoparticles Nanotechnology is becoming increasingly important for products used in our daily lives. Nanometer-sized titanium dioxide (TiO2) are widely used in industry for different purposes, such as painting, sunscreen, printing, cosmetics, biomedicine, and so on. This book summarizes the advances of TiO2 based nanobiotechnology and nanomedicine, covering materials properties, toxicological research, and biomedical application, such as antibacter, biosensing, and cancer theranostics. It uniquely integrates the TiO2 applications from physical properties, toxicology to various biomedical applications, and includes black TiO2 based cancer theranostics. Beginning with a comprehensive introduction to the properties and applications of nanoparticles, TiO2 Nanoparticles: Applications in Nanobiotechnology, Theranostics and Nanomedicine offers chapters on: Toxicity of TiO2 Nanoparticles; Antibacterial Applications of TiO2 Nanoparticles; Surface Enhanced Raman Spectrum of TiO2 Nanoparticle for Biosensing (TiO2 Nanoparticle Served as SERS Sensing Substrate); TiO2 as Inorganic Photosensitizer for Photodynamic Therapy; Cancer Theranostics of Black TiO2 Nanoparticles; and Neurodegenerative Disease Diagnostics and Therapy of TiO2-Based Nanoparticles. This title: -Blends the physical properties, toxicology of TiO2 nanoparticles to the many biomedical applications -Includes black TiO2 based cancer theranostics in its coverage -Appeals to a broad audience of researchers in academia and industry working on nanomaterials-based biosensing, drug delivery, nanomedicine TiO2 Nanoparticles: Applications in Nanobiotechnology, Theranostics and Nanomedicine is an ideal book for medicinal chemists, analytical chemists, biochemists, materials scientists, toxicologists, and those in the pharmaceutical industry.

Download or read book Photocatalysts written by Sher Bahadar Khan and published by BoD – Books on Demand. This book was released on 2019-03-06 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book enlightens the type, chemical structure, and application of photo-catalysts. It covers the recent developments in photo-catalysts and their applications, particularly in photo-catalytic degradation of different organic pollutants, hydrogen production, etc. It provides a concise but complete coverage and overview of photocatalysts and their recent advances for a broad audience: beginners, graduate students, and specialists in both academic and industrial sectors.