Download or read book Improving the Optoelectronic Property and Photoactivity of Nano structured Titanuim Dioxide written by Hong-Ying Lin and published by ProQuest. This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium dioxide (TiO 2) has been proven to be one of the most important and widely used photocatalyst for applications such as gas/liquid phase environmental cleaning, solar hydrogen generation, sensitized solar cell, UV filtration, etc. The biggest challenge in the applications of this semiconductor photocatalyst is its large band gap (~ 3.2 eV) which limits the utilizable spectrum of photons from the solar light (~ 4 to 5 %). To improve the optical sensitivity of TiO 2 in the visible light region, the band gap of TiO 2 needs to be tailored. The reduction of TiO 2 band gap can be achieved by controlling of its electronic structure via two routes: changing the particle size and doping it with impurities. To precisely control the size of TiO 2 particles, anatase TiO 2 nanocrystallines (17 to 29 nm) were synthesized by metallo-organic chemical vapor deposition (MOCVD) method with moderate control on system parameters (i.e. pressure and gas flow rates). The results of band gap change as a function of particle size agreed well with what was predicted using the Brus' effective mass model (EMM). However, the observations from photocatalytic oxidation of 2-chlorophenol (2-CP) showed that the smaller the particle size, the faster the degradation rate. This is attributed in part to the combined effect of band gap change relative to the spectrum of the light source and the specific surface area (or particle size) of the photocatalysts. Our results indicate that the gain in specific surface area due to the smaller particle size outweighs the improvement on its optical property (e.g. reduction in bandgap) under similar experimental condition. Our observation also showed the secondary particle size to be time dependent due to the aggregation and is highly correlated with its primary particle size. The nitrogen doped TiO 2 thin film synthesis was carried out with two different approaches: (1) oxidation of the titanium nitride (TiN) thin film and (2) reactive pulsed laser deposition (PLD). Nitrogen doping of TiO 2 in the former approach was done by the oxidation of TiN thin films at 800 ̊C in ambient air. The phase transformation of TiN to TiO 2 appears to be a function of annealing time. The X-ray photoelectron spectroscopy (XPS) studies have shown that the substitutionally doped TiO 2-x N x (N 1 s ~ 396 eV) remains stable only for the first two minutes of annealing. As the annealing proceeds, the N 1s XPS peak shifts to higher binding energy (N1 s ~ 400 and 402 eV) which indicates that binding energy of N atom shifted from substitutional site (Ti-N) to chemisorbed site (N=-N) when annealing process exceeds five minutes due to the substitution of Ti-N bond by Ti-O bond. Results from both depth profile XPS and cross-section TEM showed that the formation of TiO 2-x N x depends on the distance from the film surface. Film structure studied by X-ray diffraction (XRD) showed that mixed TiN and rutile TiO 2 phases formed between four and twenty four hours of annealing time. The optical properties were examined using UV-VIS spectroscopy. The most visible light sensitive samples showed ~65 to 105 nm red-shift on its absorption edges from that of pure TiO 2, which is equivalent to ~0.47 to 0.73 eV reduction in the effective bandgap. Our results suggest that surface oxidation of TiN is an effective method for the synthesis of band gap tailored oxides which have applications in photocatalysis, photovoltaic, etc. Doping of N into TiO 2 lattice was also achieved using the reactive pulsed laser deposition technique. The N concentration was controlled by adjusting the mixing ratio of make-up (N 2) and buffer (1:1 O 2 and Ar mixture) gases during laser ablation. (Abstract shortened by UMI.).
Download or read book Nanostructured Titanium Dioxide Materials written by Ali Reza Khataee and published by World Scientific. This book was released on 2012 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the past decade, research and development in the area of synthesis and applications of different nanostructured titanium dioxide have become tremendous. This book briefly describes properties, production, modification and applications of nanostructured titanium dioxide focusing in particular on photocatalytic activity. The physicochemical properties of nanostructured titanium dioxide are highlighted and the links between properties and applications are emphasized. The preparation of TiO2 nanomaterials, including nanoparticles, nanorods, nanowires, nanosheets, nanofibers, and nanotubes are primarily categorized by their preparation method (sol-gel and hydrothermal processes). Examples of early applications of nanostructured titanium dioxide in dye-sensitized solar cells, hydrogen production and storage, sensors, rechargeable batteries, electrocatalysis, self-cleaning and antibacterial surfaces and photocatalytic cancer treatment are reviewed. The review of modifications of TiO2 nanomaterials is mainly focused on the research related to the modifications of the optical properties of TiO2 nanomaterials, since many applications of TiO2 nanomaterials are closely related to their optical properties. Photocatalytic removal of various pollutants using pure TiO2 nanomaterials, TiO2-based nanoclays and non-metal doped nanostructured TiO2 are also discussed.
Download or read book Nanostructured Titanium Dioxide in Photocatalysis written by It-Meng Low and published by CRC Press. This book was released on 2021-06-18 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium dioxide (TiO2) has drawn considerable attention as an attractive inorganic raw material for various applications due to its inexpensiveness, nontoxic nature, stability, and excellent photocatalytic activity. Photocatalysis is one of the most promising route for sustainable chemistry of the 21st century. It can contribute to solving environmental, global energy, and chemical problems, as well as to the sustainable production of commodities in the near future. This book presents the fundamentals of photocatalysis in nanostructured TiO2 and describes the factors affecting the photocatalytic activity, design, and synthesis of various forms of nanostructured TiO2. It highlights the use of ion-doping and inert-atmosphere annealing to extend the light-absorption range of photocatalysts and reduce recombination between electrons and holes. It discusses numerous applications in the fields of energy and environment, such as water purification, gas sensing, storage and delivery, and energy generation. The book is an invaluable resource and useful guide for a broad readership in various fields of catalysis, materials science, environment, and energy.
Download or read book Titanium Dioxide Nanoparticles written by Yucheng Lan and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few decades, titanium dioxide has been an important material for different sectors of modern technology. More precisely, this ceramic has been synthesised in the form of nanomaterial and applied in buildings, dye-sensitised solar cells, hydrogen production, sensors, rechargeable batteries, electrocatalysis, self-cleaning, environmental pollution, and antibacterial actions based on its enhanced optical properties. This book describes preparation, photocatalytic properties, and applications of nanostructured titanium dioxide with a particular focus on non-traditional syntheses and brookite. Titanium oxide nanoparticles are produced by hydrothermal processes, ionic liquid-assisted reactions, biological approaches, ball-milling techniques, etc. Physical properties and potential future applications of the produced nanostructured titanium dioxide nanoparticles are reviewed. Toxicity of titanium oxide nanoparticles and titanium oxide nanowires are also discussed.
Download or read book Titanium Dioxide Nanoparticles written by Yucheng Lan and published by . This book was released on 2017 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few decades, titanium dioxide has been an important material for different sectors of modern technology. More precisely, this ceramic has been synthesized in the form of nanomaterial and applied in buildings, dye-sensitized solar cells, hydrogen production, sensors, rechargeable batteries, electrocatalysis, self-cleaning, environmental pollution, and antibacterial actions based on its enhanced optical properties. This book describes preparation, photocatalytic properties, and applications of nanostructured titanium dioxide with a particular focus on non-traditional syntheses and brookite. Titanium oxide nanoparticles are produced by hydrothermal processes, ionic liquid-assisted reactions, biological approaches, ball-milling techniques, etc. Physical properties and potential future applications of the produced nanostructured titanium dioxide nanoparticles are reviewed. Toxicity of titanium oxide nanoparticles and titanium oxide nanowires are also discussed.
Download or read book Titanium Dioxide written by Magdalena Janus and published by BoD – Books on Demand. This book was released on 2017-07-26 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium dioxide is mainly used as a pigment and photocatalyst. It is possible to find it in food, cosmetics, building materials, electric devices, and others. This book contains chapters about characteristics of anatase and rutile crystallographic structure of titanium dioxide and the use of theoretical calculation for photoactivity determination.
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 Optical Properties Electronic Structures and High Pressure Study of Nanostructured One Dimensional Titanium Dioxide by Synchrotron Radiation and Spectroscopy written by Ankang Zhao and published by . This book was released on 2013 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: One dimensional (1D) titanium dioxide (TiO2) nanomaterials have been extensively studied in recent years due to their superior electrical, optical mechanical and chemical properties compared with their bulk counterparts. Two different kinds of 1D TiO2 nanomaterials, TiO2 nanowires (TiO2 NW) and TiO2 nanotubes (TiO2 NT), are studied in this thesis by using various techniques. In one study, TiO2 NW synthesized by hydrothermal method and a series of calcinated TiO2 NW were investigated by using absorption near edge structures (XANES), X-ray diffraction (XRD) and X-ray excited optical luminescence (XEOL). It is found that TiO2 NW as synthesized undergo a phase transition under calcination: TiO2-B phase transformed to anatase phase and then to rutile phase. Moreover, a green photoluminescence (PL) started showing up at a wavelength of 470 nm at 650 °C, then shifts to 550 nm at 750 °C and finally at 1000 °C the green PL disappears and near infrared (IR) PL was observed. Also optical behaviours are consistent with the phase transformation sequence. The green PL at 550 nm and near IR PL at 830 nm is attributed to oxygen vacancies of anatase phase and the bulk defects of rutile phase respectively. However, a new phenomenon is observed, the green PL observed at 470 nm. Considering this green PL is consistent with the presence of the TiO2-B phase, it is proposed that the green PL at 470 is due to the TiO2-B phase. In another study, the high-pressure behaviour of anatase TiO2 NT is studied using Raman and synchrotron X-ray diffraction at increasing pressure up to 31.1 GPa. Upon compression, anatase phase directly transforms to baddeleyite phase at ̃12.2 GPa, Besides, we found in the compression of anatase phase, (1) a higher compressibility along c-axis is observed compared to a-axis, which may be due to crystal structure and growth direction of TiO2 NT, and (2) and the bulk modulus is 164 GPa which is much lower than that of other TiO2 nanomaterials. Upon decompression, the -PbO2 phase is retrieved at ambient pressure and a compression-decompression cycle is finished. These results indicate that the 1D morphology of TiO2 NT may be responsible for its high-pressure transition and bulk modulus.
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 Novel Preparation of Nanostructured Titanium Dioxide Photocatalytic Particles Films Membranes and Devices for Environmental Applications written by Hyeok Choi and published by . This book was released on 2007 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: From a scientific point of view, this study will provide new nanotechnological and materials chemistry procedures to synthesize highly efficient photocatalytic TiO2 particles, films, and membranes that can be used for the treatment and disinfection of water and wastewater under even visible light irradiation, and highly sensitive TiO2-based devices for the development of new type of sensors.
Download or read book Titanium Dioxide Nanomaterials Volume 1352 written by Xiaobo Chen and published by Materials Research Society. This book was released on 2011-11-28 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium dioxide nanomaterials have been showing very promising applications in many fields. Scientists from all over the world have gathered together to discuss the most recent advances in areas spanning from theoretical calculations to fundamental surface science and to materials fabrication, characterization and practical exploitation. More than 160 papers, presentations and posters, were accepted in Symposium GG, "Titanium Dioxide Nanomaterials," at the 2011 MRS Spring Meeting held April 25-29 in San Francisco, California. In this volume are some of the selected papers which cover the synthesis, properties, and applications of titanium dioxide nanomaterials.
Download or read book Heterogeneous Photocatalysis written by M. Schiavello and published by . This book was released on 1997-10-09 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysis is a reaction which is accelerated by light while a heterogeneous reaction consists of two phases ( a solid and a liquid for example). Heterogeneous Photocatalysis is a fast developing science which to date has not been fully detailed in a monograph. This title discusses the basic principles of heterogeneous photocatalysis and describes the bulk and surface properties of semiconductors. Applications of various types of photoreactions are described and the problems related to the modeling and design of photoreactors are covered.
Download or read book Nanotechnology Applications for Clean Water written by Anita Street and published by William Andrew. This book was released on 2014-05-15 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanotechnology is already having a dramatic impact on improving water quality and the second edition of Nanotechnology Applications for Clean Water highlights both the challenges and the opportunities for nanotechnology to positively influence this area of environmental protection. This book presents detailed information on cutting-edge technologies, current research, and trends that may impact the success and uptake of the applications. Recent advances show that many of the current problems with water quality can be addressed using nanosorbents, nanocatalysts, bioactive nanoparticles, nanostructured catalytic membranes, and nanoparticle enhanced filtration. The book describes these technologies in detail and demonstrates how they can provide clean drinking water in both large scale water treatment plants and in point-of-use systems. In addition, the book addresses the societal factors that may affect widespread acceptance of the applications. Sections are also featured on carbon nanotube arrays and graphene-based sensors for contaminant sensing, nanostructured membranes for water purification, and multifunctional materials in carbon microspheres for the remediation of chlorinated hydrocarbons. Addresses both the technological aspects of delivering clean water supplies and the societal implications that affect take-up Details how the technologies are applied in large-scale water treatment plants and in point-of-use systems Highlights challenges and the opportunities for nanotechnology to positively influence this area of environmental protection
Download or read book Plasma Electrolytic Oxidation PEO Coatings written by Marta Mohedano and published by MDPI. This book was released on 2021-06-02 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma electrolytic oxidation (PEO), also known as micro-arc oxidation (MAO), functionalizes surfaces, improving the mechanical, thermal, and corrosion performance of metallic substrates, along with other tailored properties (e.g., biocompatibility, catalysis, antibacterial response, self-lubrication, etc.). The extensive field of applications of this technique ranges from structural components, in particular, in the transport sector, to more advanced fields, such as bioengineering. The present Special Issue covers the latest advances in PEO‐coated light alloys for structural (Al, Mg) and biomedical applications (Ti, Mg), with 10 research papers and 1 review from leading research groups around the world.
Download or read book Synthesis and Electrochemical Studies of Titanium Dioxide Based Nanostructured Catalysts for Environmental Applications written by Xin Chang and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials are playing an increasingly important role toward addressing emerging environmental challenges. Heterogeneous catalysis is the best option available for the elimination of environmentally incompatible compounds that reside within contaminated water sources. Among all investigated nanomaterials, TiO2 has proven itself as optimal for various applications such as photocatalysis, electrochromic devices, dye sensitized solar cells, hydrogen production, and sensing. TiO2 is impressive due to its low cost, non-toxicity, chemical inertness, and high efficiency. In spite of having all these excellent properties, the efficient utilization of TiO2 for various applications is limited by its inability to absorb visible light. Due to large band gap, only UV light may be absorbed by TiO2, thus making it minimally efficient when exposed to sunlight, which contains only about 4% in the UV spectrum. An enormous amount of research has been focused on decreasing the band gap of TiO2 in order to increase its efficiency under sunlight. The present research is focused on the development of new techniques to increase the conductivity of TiO2 nanomaterials as well as to decrease its band gap to make it an efficient photoelectrocatalyst. During my PhD study, TiO2 nanostructured materials were fabricated using a facile anodization method. TiO2 nanotubes were synthesized by employing DMSO + 2% HF as an electrolyte. An electrochemical (EC) reduction method was employed to reduce the TiO2 nanotubes, which were subsequently employed as a novel and efficient catalyst for the oxidation of salicylic acid (SA) for the first time. The effects of the cathodic current and reduction time on the electrocatalytic activity of the reduced TiO2 were investigated, and the results revealed that the optimal electrochemical treatment conditions were −5 mA cm−2 for 10 min. The electrochemically treated TiO2 nanotubes possessed a much higher overpotential for oxygen evolution than a commercial Pt electrode, and exhibited a high electrocatalytic activity in the oxidation of SA. When compared with a Pt electrode, the electrochemically treated TiO2 nanotubes exhibited ca. 6 times higher activity toward the oxidation of SA. The high electrocatalytic activity and stability of the treated TiO2 nanotubes enabled by the facile electrochemical reduction may be attributed to the decrease of Ti(IV), the increase of Ti(II) and Ti(III), and the increase of oxygen vacancies, as well as a significant improvement in the donor density. The effects of TiO2 nanotube length on its activity in the electrocatalytic oxidation of lignin were also studied. The TiO2 nanotubes were grown in a DMSO and 2% HF solution, where a constant potential was applied for different time intervals. A very uniform increase in the lengths of the nanotubes was observed when the anodization time interval was increased. The increase in the nanotube length had a very significant effect on the electrochemical oxidation of lignin. The rate of lignin oxidation continued to increase until an optimal length was achieved. Impedance studies revealed that there was an optimal length of nanotube that demonstrated the least charge transfer resistance; if longer nanotubes were grown a higher resistant was obtained. The fabricated electrode also showed a very high level of stability. Nanoporous TiO2 was directly grown employing a three-step electrochemical anodization process in ethylene glycol + 0.3 wt% NH4F + 2 wt% H2O. A significant enhancement in the photocatalytic activity of nanoporous TiO2 was achieved via a facile electrochemical reduction. Subsequently, the treated nanoporous TiO2 was investigated as a catalyst for photoelectrochemical water splitting and the photoelectrochemical oxidation of Rhodamine B (Rh B), which is an organic dye pollutant. Due to the presence of higher degree of ordering and a larger surface area, the nanoporous TiO2 electrode showed a much higher photocurrent under UV light in contrast to TiO2 nanotubes. The photocurrent of the as-prepared nanoporous TiO2 was 7.70 mA cm−2 at 1.5 V, and it was significantly increased to 46.23 mA cm−2 following additional electrochemical treatment. The electron donor density of the electrochemically treated nanoporous TiO2 was four orders of magnitude higher than that of the untreated nanoporous TiO2. The treated nanoporous TiO2 also demonstrated six times more rapid photoelectrochemical degradation of Rh B, as well as remarkable stability. The high surface area of electrochemically reduced nanoporous TiO2 may be used as a substrate to synthesize a Pt and Pb co-deposited bifunctional electrode (PtPb/EC-TiO2) to enable photo-assisted methanol oxidation in a direct methanol fuel cell (DMFC). Photochemical deposition was employed to introduce Pt and Pb onto the nanoporous TiO2 surface at an equimolar ratio. Mott-Shottky plots and Nyquist plots revealed that the PtPb/EC-TiO2 bifunctional electrode showed a higher electron donor density and a much lower charge transfer resistance as compared to the Pt/EC-TiO2, whether in the dark or under solar light irradiation. PtPb/EC-TiO2 exhibited a further enhancement in activity when solar light irradiation is applied to the electrode thus making it an efficient bifunctional electrode. III The simplicity and efficacy of the novel electrochemical reduction approach developed in this study facilitates the integration of TiO2 nanostructured materials into the design of high-performance energy harvesting and water purification technologies.
Download or read book Semiconductor Photocatalysis written by Wenbin Cao and published by BoD – Books on Demand. This book was released on 2016-08-24 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysis is a hot topic because it is an environmentally friendly approach toward the conversion of light energy into chemical energy at mild reaction environments. Also, it is well applied in several major areas such as water splitting, bacterial inactivation, and pollutants elimination, which is a possible solution to energy shortage and environmental issues. The fundamental knowledge and the frontier research progress in typical photocatalytic materials, such as TiO2-based and non-TiO2-based photocatalysts, are included in this book. Methods to improve the photocatalytic efficiency and to provide a hint for the rational design of the new photocatalysts are covered.
Download or read book Nanostructured Titanium Dioxide for Functional Coatings written by Indriana Kartini and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthesis routes to nanostructured titanium dioxides (spherical nanoparticles, nanotubes, mesostructure) have been studied. Their potential applications in various fields based on coating technology have been explored, id est, dye-sensitized solar cells (using ruthenium sensitizer and some results of natural dyes), photocatalysts for self-cleaning films (TiO2 on textiles), antibacterial coating for multifunctional textiles (TiO2-SiO2 on cotton), and recent result on antifouling coating on wood. The synthesis/preparation procedures were developed to obtain green protocols based on combined techniques of hydro- or solvo-thermal (templated, seeded, deposition), sol-gel (templated, room temperature, dip coating), and solvent-casting techniques. Discussion on the properties and synthesis mechanism is presented. It will be shown that sonication has important role to shorten the preparation of nanotube titania and has been proposed as one green synthesis route. The changing of morphology of titanium dioxide has presented unexpected results to the shifting of photoactivity into visible irradiation.
