Download or read book Synthesis of Rare Earth Doped TiO2 Nanorods as Photocatalysts for Lignin Degradation written by and published by . This book was released on 2015 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper, a two-step process is developed to synthesize rare earth doped titania nanorods (RE-TiO2 NRs) as photocatalysts for efficient degradation of lignin under simulated sunlight irradiation. In this approach, protonated titanate nanotubes with layered structures were first prepared by a hydrothermal approach, and rare earth metal ions were subsequently bound to the negatively charged surface of the synthesized titanate via electrostatic incorporation. The as-synthesized RE-TiO2 NRs after calcination generally showed much higher photocatalytic efficiencies than those of undoped TiO2 NRs or the commercial P25 TiO2 photocatalyst. Using methyl orange (MO) as a probing molecule, we demonstrate that Eu-TiO2 NRs are among the best for degrading MO, with an observed rate constant of 4.2 × 10-3 s-1. The La3+, Sm3+, Eu3+ and Er3+ doped TiO2 NRs also showed higher photocatalytic efficiencies in degrading MO than the commercial P25 TiO2. Finally, we further demonstrate that lignin can be photodegraded effectively and rapidly at room temperature under simulated sunlight through two reaction routes, which could be important in controlling ways of lignin depolymerization or the formation of reaction products.
Download or read book Synthesis of TiO 1tn2 Based Nanoparticles for Photocatalytic Applications written by Kranthi Kumar Akurati and published by Cuvillier Verlag. This book was released on 2008 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Titanium Dioxide Photocatalysis written by Vladimiro Dal Santo and published by MDPI. This book was released on 2019-05-27 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although the seminal work of Fujishima et al. dates back to 1971, TiO2 still remains the most diffused and studied semiconductor, employed in photo-oxidation processes for cleantech (i.e., polluted water and air treatment), in solar fuel production (mainly hydrogen production by water photo splitting), and in Carbon Capture and Utilization (CCU) processes by CO2 photoreduction. The eleven articles, among them three reviews, in this book cover recent results and research trends of various aspects of titanium dioxide photocatalysis, with the chief aim of improving the final efficiency of TiO2-based materials. Strategies include doping, metal co-catalyst deposition, and the realization of composites with plasmonic materials, other semiconductors, and graphene. Photocatalysts with high efficiency and selectivity can be also obtained by controlling the precise crystal shape (and homogeneous size) and the organization in superstructures from ultrathin films to hierarchical nanostructures. Finally, the theoretical modeling of TiO2 nanoparticles is discussed and highlighted. The range of topics addressed in this book will stimulate the reader’s interest as well as provide a valuable source of information for researchers in academia and industry.
Download or read book Hydrothermal Synthesis of Cr Doped TiO2 Nanorods for the Application of Photocatalyst written by 阮氏黃豔 and published by . This book was released on 2013 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Nitrogen doped Titanium Oxide Nanoparticles for Visible light Photocatalytic Wastewater Treatment written by Mohammad Ali Pelaschi and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: TiO2 nanoparticles are one of the most suitable materials for photocatalysis, specifically for water and air treatment and removal of a wide variety of organic pollutants such as dyes, aromatic compounds, and chlorinated aromatic compounds. Methods of synthesis of TiO2 are generally categorized in two main classes of wet chemical, and dry methods. Wet chemical methods generally provide a better control over size, size distribution, and shape; all of which significantly affect photocatalytic performance of the produced nanoparticles. Despite its advantages over other semiconductor photocatalysts, wide band-gap of titania restrains its photocatalytic activity to only UV light, which only makes up to 5% of the light reaching surface of the earth. To induce visible-light activity, titania has been doped by different dopants, including transition metal-dopants such as Fe, and Co and non-metal dopants such as N, and C. Nitrogen has been shown to be a better dopant, providing a suitably placed energy state within the band-gap of TiO2, and not suffering from issues related to transition-metal dopants such as low thermal and physical stability and high electron-hole recombination rates. To dope titania with nitrogen, one could add the nitrogen source together with other precursors during synthesis, referred to as wet chemical doping methods, or anneal the synthesized titania nanoparticles under a flow of ammonia at high temperatures, referred to as dry doping methods. While different doping methods have been studied individually, the author maintains that there has been an absence of research comparing the effectiveness of these methods, on photocatalytic performance of N-doped TiO2 within a consistent experiment. In this research TiO2 nanoparticles were synthesized by a facile, inexpensive sol-gel method, and doping was done by wet chemical methods, dry methods, and a combination of both these methods. Visible-light photocatalytic activity of these nanoparticles was evaluated by their efficiency in degradation of methyl orange. The results show wet doping methods increase the efficiency of titania nanoparticles more than dry doping, or combination of both. Further investigation showed that the main reason for higher activity of wet chemically doped nanoparticles is due to their higher available surface area of 131.7 m2.g-1. After normalizing the available surface area, measured by the BET method, it was shown that a combination of wet chemical doping, and dry doping at 600 °C result in the most active nanoparticles, but high temperature dry doping severely decreases the surface area, lowering the overall efficiency of the product. Additionally, N-doped TiO2 nanoparticles were synthesized using a simple hydrothermal method, in which the nitrogen source was used not only to dope, but also to control shape, size, size distribution, and morphology of the titania nanoparticles, and to induce aqueous colloidal stability. It was shown that addition of triethylamine during the synthesis, results in ultra-small, colloidally stable, cubic TiO2 nanoparticles, while using triethanolamine results in formation of TiO2 pallets, assembled into spherical, rose-like structures. The synthesized nanoparticles show impressive efficiency in visible-light removal of phenol, 4-chlorophenol, and pentachlorophenol, achieving 100% degradation of a 100-ppm phenol solution in 90 min, more than 98% degradation of a 20-ppm 4-chlorophenol solution in 90 min, and 97% degradation of a 10-ppm pentachlorophenol in 180 min with 500 ppm loading of the catalyst in all cases. Moreover, synthesized nanoparticles showed no sign of deactivation after 5 consecutive runs, removing 4-chlorophenol, showing their reusability.
Download or read book Preparation and Characterization of Rare Earth Ions doped TiO2 Photocatalyst Film by RF magnetron Sputtering written by Suthin Yuenyaw and published by . This book was released on 2010 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Copper Doped Titanium Dioxide TiO2 Nanoparticles for Enhanced Photocatalytic Activity Under Visible Light Irradiation written by Sheng Yau Leong and published by . This book was released on 2013 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Titanium dioxide (TiO2) is best known for its inexpensiveness and highly available as a photocatalyst. However, due to its wide-bandgap of 3.2 eV and the fast recombination of electron-hole pair, they have contributed to the inability to use the sunlight sufficiently as well as hindering for any reaction to happen. The objectives of the title are to synthesize a copper (Cu) doped TiO2, to inspect the photocatalytic activity of the synthesized TiO2 and to study the kinetic of the degradation of methylene blue (MB). A Cu salt is first synthesized using copper nitrate (Cu(NO3)) mixed in the glycerol phase. The preparation of TiO2 was carried out by the sol-gel method and the resulted Cu salt is added into it to in a 10 wt.% Cu/TiO2 manner. The resulted gel was aged for a day before it was heated up in the oven for 24 hours, which resulted in powder form. It was grinded and calcinated at 300 oC for an hour. The photocatalytic activity of the synthesized catalyst was inspected with the degradation of methylene blue (MB). As a result, the photocatalytic activity had been increased and the K0 ((k0H/K0)+ k0 is 0.03236 mg L-1 min-1 while K0 is 9.32615 X 10-3 4L mg-1.
Download or read book Synthesis of Ag doped TiO2 Nanoparticles by Combining Laser Decomposition of Titanium Isopropoxide and Ablation of Ag for Dye sensitized Solar Cells written by Ahmed Kamal Al-Kamal and published by . This book was released on 2015 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanostructured powders of TiO2 and Ag-doped TiO2 are synthesized by a novel pulsed-laser process that combines laser ablation of a silver (Ag) disc with laser decomposition of a titanium tetra-isopropoxide (TTIP) solution. Nanoparticles are formed by rapid condensation of vaporized species in the plasma plume generated by the high power laser, resulting in the formation of rapidly quenched Ag-doped TiO2 nanoparticles that have far-from-equilibrium or metastable structures. The uniqueness of the new ablation process is that it is a one-step process, in contrast to the two-step process developed by previous researchers in the field. Moreover, its ability to synthesize an extended-solid solution phase of Ag in TiO2 may also be unique. The present work implies that other oxide phases, such as Al2O3, MgO and MgAl2O4, can be doped with normally insoluble metals, such as Pt and Ir, thus opening new opportunities for catalytic applications. Again, there is the prospect of being able to synthesize nanopowders of diamond, cBN, and mixtures thereof, which are of interest for applications in machine tools, rock-drill bits, and lightweight armor. A wet-chemistry method is also investigated, which has much in common with that adopted by previous workers in the field. However, photo-voltaic properties do not measure up to expectations based on published data. A possible explanation is that the selected Ag concentrations are too high, so that recombination of holes and electrons occurs via a quantum-tunneling mechanism reduces photo-activity. Future work, therefore, will investigate lower concentrations of Ag dopant in TiO2, while also examining the effects of metastable states, including extended solid solution, amorphous, and semi-crystalline structures.
Download or read book Synthesis of Iron Doped Titania and Its Application in Degradation of Organic Pollution in Water written by Vahid Moradi and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Anatase TiO2 has attracted a lot of attention due to its applications as a photocatalyst in water and air treatment technologies. However, its large band gap energy (⁓3.2 eV) limits its application only to UV light. Also, anatase TiO2 suffers from high electron/hole recombination, which diminishes its photocatalytic activity. Therefore, different methods have been employed to decrease its band gap energy and reduce the recombination of the charge carriers. One of the methods is to incorporate impurities as dopants in its crystal lattice. Different metal and non-metal dopants have been studied for this aim. Among the different choices, Fe3+ has showed a great potential to improve the photocatalytic activity of TiO2 under visible light irradiation. Firstly, the d orbitals of Fe3+ interact with the 3d orbitals of Ti4+ generating intermediate band gap energy levels to facilitate excitation of electrons under visible light by a red shift in the absorption of light. Secondly, Fe3+ can interact with both electrons and holes to produce Fe2+ and Fe4+ trapping the charge carriers and reducing their recombination rate. Fe2+ and Fe4+ can release the electron and hole and revert back to the Fe3+. The released charge carriers migrate to the surface of the nanoparticles to initiate the photocatalytic reactions. However, it was found that the photocatalytic activity of Fe-TiO2 is not as high as expected. Therefore, in this research study I investigated the cause for its low photocatalytic activity and found methods to improve it. The Fe-TiO2 was synthesized using a facile sol-gel method and its structure and properties were characterized by different instrumental techniques. Using TEM and HRTEM an amorphous layer was seen on the surface of the nanoparticles. This layer characterized using XPS and EDX was composed of iron oxide layers. This layer was contaminating the surface of the nanoparticles where the photocatalytic reactions take place. Moreover, the contamination layer was acting as a recombination center for the electrons and holes. To the best of our knowledge, no previous study was conducted to investigate the effect of an iron oxide contamination layer on the photocatalytic activity of Fe-TiO2 nanoparticles. This layer was removed using a concentrated HCl solution confirmed using HRTEM and XPS. Also, using DRS it was shown that its removal does not effect the optical properties of the Fe-TiO2 confirming that the acid treatment process did not influence the doped Fe3+ in the TiO2 crystal lattice. The degradation of methelyne orange (MO), a representative pollutant, was increased from 25% to 98% under visible light irradiation. Also, in order to achieve the highest performance of the photocatalyst, it was necessary to study the parameters of the photocatalytic activity and the degradation efficiency. Therefore, experiments using a phenol solution, another representative pollutant, were conducted to investigate and optimize the effects of the catalyst load, reaction time, initial concentrating of the pollutant and pH. The degradation efficiency of the phenol solution was found to increase from 31% to 57% by the removal of the contamination layer and by controlling the pH of the solution.
Download or read book Green Photocatalytic Semiconductors written by Seema Garg and published by Springer Nature. This book was released on 2021-09-20 with total page 855 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book comprises a detailed overview on the role of photocatalysts for environmental remediation, hydrogen production and carbon dioxide reduction. Effective ways to enhance the photocatalytic activity of the material via doping, hybrid material, laser light and nanocomposites have been discussed in this book. The book also further elaborates the role of metal nanoparticles, rare earth doping, sensitizers, surface oxygen vacancy, interface engineering and band gap engineering for enhancing the photocatalytic activity. An approach to recover the photocatalytic material via immobilization is also presented. This book brings to light much of the recent research in the development of such semiconductor photocatalytic systems. The book will thus be of relevance to researchers in the field of: material science, environmental science & technology, photocatalytic applications, newer methods of energy generation & conversion and industrial applications.
Download or read book Photocatalysis written by Dionysios D Dionysiou and published by Royal Society of Chemistry. This book was released on 2016-03-30 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: From environmental remediation to alternative fuels, this book explores the numerous important applications of photocatalysis. The book covers topics such as the photocatalytic processes in the treatment of water and air; the fundamentals of solar photocatalysis; the challenges involved in developing self-cleaning photocatalytic materials; photocatalytic hydrogen generation; photocatalysts in the synthesis of chemicals; and photocatalysis in food packaging and biomedical and medical applications. The book also critically discusses concepts for the future of photocatalysis, providing a fascinating insight for researchers. Together with Photocatalysis: Fundamentals and Perspectives, these volumes provide a complete overview to photocatalysis.
Download or read book Powder Surface Area and Porosity written by S. Lowell and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rapid growth of interest in powders and their surface properties in many diverse industries prompted the writing of this book for those who have the need to make meaningful measurements without the benefit of years of experience. It is intended as an introduction to some of the elementary theory and experimental methods used to study the surface area, porosity and density of powders. It may be found useful by those with little or no training in solid surfaces who have the need to quickly learn the rudiments of surface area, density and pore-size measurements. Syosset, New York S. Lowell May, 1983 J. E. Shields Xl List of symbols Use of symbols for purposes other than those indicated in the following list are so defined in the text. Some symbols not shown in this list are defined in the text. d adsorbate cross-sectional area A area; condensation coefficient; collision frequency C BET constant c concentration D diameter; coefficient of thermal diffusion E adsorption potential f permeability aspect factor F flow rate; force; feed rate 9 gravitational constant G Gibbs free energy GS free surface energy h heat of immersion per unit area; height H enthalpy Hi heat of immersion Hsv heat of adsorption BET intercept; filament current k thermal conductivity; specific reaction rate K Harkins-Jura constant I length L heat of liquefaction M mass M molecular weight n number of moles N number of molecules; number of particles N Avagadro's number .
Download or read book Nanotechnology in Industrial Wastewater Treatment written by Dr. Arup Roy and published by IWA Publishing. This book was released on 2015-01-15 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanotechnology in Industrial Wastewater Treatment is a state of the art reference book. The book is particularly useful for wastewater technology development laboratories and organizations. All professional and academic areas connected with environmental engineering, nanotechnology based wastewater treatment and related product design are incorporated and provide an essentialresource. The book describes the application and synthesis of Ca-based and magnetic nano-materials and their potential application for removal/treatment of heavy metals from wastewater. Nanotechnology in Industrial Wastewater Treatment discusses the rapid wastewater treatment methods using Ca-based nanomaterials and magnetic nanomaterials. This is an emerging area of new science and technology in wastewater treatment. The main audiences for the book are water industry professionals, research scholars and students in the area of Environmental Engineering and Nanotechnology. Authors: Dr. Arup Roy Department of Mining Engineering, Geo-Environmental Lab., Indian Institute of Technology, Kharagpur,India; and Professor Jayanta Bhattacharya, Department of Mining Engineering, Geo-Environmental Lab., Indian Institute of Technology, Kharagpur, India.
Download or read book Sonochemistry written by Juan Carlos Colmenares and published by Springer. This book was released on 2017-03-15 with total page 287 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.
Download or read book Environmental Remediation Through Carbon Based Nano Composites written by Mohammad Jawaid and published by Springer Nature. This book was released on 2020-09-25 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines carbon-based nanocomposite materials and their application in various environmental fields, such as wastewater treatment, and air and soil remediation. Featuring illustrations, and tables summarizing the latest research, it gathers up-to-date information on the application of carbon nanocomposites in the removal of environmental pollutants from different sources. Given its scope, the book is a valuable textbook for research students, and a useful handbook and reference resource for researchers, academics and industrial scientists working in the field of environmental pollutants and their safe removal.
Download or read book Photoelectrocatalysis written by Leonardo Palmisano and published by Elsevier. This book was released on 2022-10-21 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photoelectrocatalysis: Fundamentals and Applications presents an in-depth review of the topic for students and researchersworking on photoelectrocatalysis-related subjects from pure chemistry to materials and environmental chemistry inorder to propose applications and new perspectives. The main advantage of a photoelectrocatalytic process is the mildexperimental conditions under which the reactions are carried out, which are often possible at atmospheric pressure androom temperature using cheap and nontoxic solvents (e.g., water), oxidants (e.g., O2 from the air), catalytic materials (e.g.,TiO2 on Ti layer), and the potential exploitation of solar light. This book presents the fundamentals and the applications of photoelectrocatalysis, such as hydrogen production fromwater splitting, the remediation of harmful compounds, and CO2 reduction. Photoelectrocatalytic reactors and lightsources, in addition to kinetic aspects, are presented along with an exploration of the relationship between photocatalysisand electrocatalysis. In addition, photocorrosion issues and the application of selective photoelectrocatalytic organictransformations, which is now a growing field of research, are also reported. Finally, the advantages/disadvantages andfuture perspectives of photoelectrocatalysis are highlighted through the possibility of working at a pilot/industrial scale inenvironmentally friendly conditions. Presents the fundamentals of photoelectrocatalysis Outlines photoelectrocatalytic green chemistry Reviews photoelectrocatalytic remediation of harmful compounds, hydrogen production, and CO2 reduction Includes photocorrosion, photoelectrocatalytic reactors, and modeling along with kinetic aspects
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.
