Influence of Oxygen Pressure to Photocatalytic Oxidation of Phenol on CuO/TiO2 PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Influence of Oxygen Pressure to Photocatalytic Oxidation of Phenol on CuO/TiO2 PDF full book. Access full book title Influence of Oxygen Pressure to Photocatalytic Oxidation of Phenol on CuO/TiO2 by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Author: Rajesh J. Tayade
Publisher: Trans Tech Publications Ltd
ISBN: 3035730210
Category : Technology & Engineering
Languages : en
Pages : 180
Get Book Here
Book Description
This special topic volume on Photocatalytic Materials and Surfaces for Environmental Cleanup IV addresses photocatalysis in wide sense focus on the environmental applications of photocatalytic materials. Photocatalytic materials had been widely studied for the various applications such as water and air purification, CO2 reduction, hydrogen generation, and development of auto-cleaning surfaces etc. The present special topic volume covers the application of various photocatalytic materials for CO2 reduction, hydrogen generation, removal of pesticides, degradation of organic pollutant and recent development in the fabrication of photocatalytic reactors.
Author: Lindelwa Jay
Publisher:
ISBN:
Category : Water
Languages : en
Pages : 0
Get Book Here
Book Description
The United States Environmental Protection Agency (USEPA) has enlisted phenolic compounds as pollutants of priority concern, as they tend to persist in the environment over a long period, accumulate and exert toxic effects on humans and animals. The entrance of phenolic compounds into the aquatic environment results from natural, industrial, domestic and agricultural activities. Their presence may be due to the degradation or decomposition of natural organic matter present in the water, through the disposal of industrial and domestic wastes into water bodies and through runoffs from agricultural land. Several specific new technologies, called Advanced Oxidation Processes (AOP), have been developed to eliminate dangerous organic chemicals such as phenol from polluted waters. The photocatalytic process, based on UV irradiated semiconductor (TiO2), represents one of AOP that provide an interesting route to the destruction of many organic substances to CO2, H2O and corresponding mineral acids. TiO2 is usually used as a photocatalyst in two crystal structures: Rutile and Anatase. The photoreactivity of P-25 Degussa, consisting of anatase and rutile (4/1 w/w), exceeds that of pure anatase and rutile in several reaction systems. This study characterised the three TiO2 powder forms by BET, XRD, XRF and SEM analyses to contribute to a better understanding of their physical properties. Anatase was revealed to have 98.4% purity x-ray fluorescence analysis, Degussa at 96.7% and rutile at 75.7% was reported to have the most impurities (~25%). This study investigated the UV/TiO2 photocatalytic degradation of phenol, with emphasis on the effects of; solution pH, catalyst load, initial phenol concentration, dissolved oxygen and UV radiation intensity. Degradation studies were conducted in a batch reactor with photons for catalyst (TiO2) activation supplied by a medium pressure 400 W UV lamp immersed in the pollutant solution housed in a double jacket quartz sleeve, which served as the cooling system for the lamp. Temperature control in the reactor was achieved by circulating cold water through the outer cavity of the quartz sleeve. The reactor contents in all batches were aerated at a flow rate of 10 mL/min. Thorough mixing of the contents of the reactor was achieved by continuous agitation with a magnetic stirrer. The experimental reaction time was set at 60-100minutes. Samples were monitored by GC-MS analysis. Results showed that UV/TiO2 photocatalysis is an effective method for the removal of phenol from wastewaters. The efficiency of the process depends strongly on the experimental conditions. Degradation of organic compounds in water is often accompanied by the formation of several intermediate compounds, some of which may be more toxic than the original pollutant. The carbon-13 isotopic labelling technique was employed to track the degradation mechanism of phenol to better understand the degradation pathway. Carbon-13 tracking results revealed that hydroquinone, catechol, benzoquinone, resorcinol and maleic acid were the main intermediates containing the C-13 isotope. A reaction pathway was postulated based on these findings. Kinetic isotope effect (KIE) experiments were conducted and a primary isotope effect was observed. This confirmed that the C-13 isotope position on the labelled phenol was the site of bond breaking in the rate-limiting step.
Author: Hong-Ying Lin
Publisher: ProQuest
ISBN: 9780549821137
Category : Nanostructures
Languages : en
Pages :
Get Book Here
Book Description
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.).
Author: Hiromi Yamashita
Publisher: Springer
ISBN: 3319260790
Category : Science
Languages : en
Pages : 543
Get Book Here
Book Description
While books on semiconductor TiO2 photocatalysis are legion, nanostructured controlled photocatalysts are attractive beyond standard semiconductors, and this book is devoted to the many novel uses of advanced TiO2 and MOF-based photocatalysts. Details on synthesis, characterization, and reaction applications of nanostructured photocatalysts are summarized. Other new materials discussed in this book are Bi- W- oxides, metal complexes, and unique porous materials. This book contains methods of preparation and characterization of unique nanostructured photocatalysts, and details about their catalytic action. Contributors to this volume are leading Asian researchers in Photocatalysis. It will appeal to researchers wishing to know how to design new types of photocatalysts with controlled nanostructures.
Author: Marcos Soto-Hernández
Publisher: BoD – Books on Demand
ISBN: 9535129570
Category : Science
Languages : en
Pages : 458
Get Book Here
Book Description
Phenolic compounds as a large class of metabolites found in plants have attracted attention since long time ago due to their properties and the hope that they will show beneficial health effects when taken as dietary supplements. This book presents the state of the art of some of the natural sources of phenolic compounds, for example, medicinal plants, grapes or blue maize, as well as the modern methods of extraction, quantification, and identification, and there is a special section discussing the treatment, removal, and degradation of phenols, an important issue in those phenols derived from the pharmaceutical or petrochemical industries.
Author: Satinder Ahuja
Publisher: Elsevier
ISBN: 0128147911
Category : Technology & Engineering
Languages : en
Pages : 442
Get Book Here
Book Description
Advances in Water Purification Techniques: Meeting the Needs of Developed and Developing Countries provides a variety of approaches to water purification that can help assist readers with their research and applications. Water contamination problems occur frequently worldwide, hence the most updated knowledge on water purification systems can be helpful in employing the right type of filter or other mechanism of decontamination. The problems with arsenic contamination of water in Bangladesh and the lead problem in Flint, Michigan remind us of the need to monitor water pollution rigorously, from both point and non-point sources. - Provides a valuable resource on how to solve water contamination problems or develop new approaches to water purification - Presents advanced methods for monitoring water contamination - Describes various approaches to water purification - Encourages new developments in water purification techniques - Includes methods for assessing and monitoring environmental contaminants - Covers recent advancement in molecular techniques
Author: Mario J. Muñoz-Batista
Publisher: Springer Nature
ISBN: 3030494926
Category : Science
Languages : en
Pages : 301
Get Book Here
Book Description
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.
Author: Kostas Triantafyllidis
Publisher: Newnes
ISBN: 0444563326
Category : Technology & Engineering
Languages : en
Pages : 607
Get Book Here
Book Description
The Role of Catalysis for the Sustainable Production of Bio-fuels and Bio-chemicals describes the importance of catalysis for the sustainable production of biofuels and biochemicals, focused primarily on the state-of-the-art catalysts and catalytic processes expected to play a decisive role in the "green" production of fuels and chemicals from biomass. In addition, the book includes general elements regarding the entire chain of biomass production, conversion, environment, economy, and life-cycle assessment. Very few books are available on catalysis in production schemes using biomass or its primary conversion products, such as bio-oil and lignin. This book fills that gap with detailed discussions of: - Catalytic pyrolysis of lignocellulosic biomass - Hybrid biogasoline by co-processing in FCC units - Fischer-Tropsch synthesis to biofuels (biomass-to-liquid process) - Steam reforming of bio-oils to hydrogen With energy prices rapidly rising, environmental concerns growing, and regulatory apparatus evolving, this book is a resource with tutorial, research, and technological value for chemists, chemical engineers, policymakers, and students. - Includes catalytic reaction mechanism schemes and gives a clear understanding of catalytic processes - Includes flow diagrams of bench-, pilot- and industrial-scale catalytic processing units and demonstrates the various process technologies involved, enabling easy selection of the best process - Incorporates many tables, enabling easy comparison of data based on a critical review of the available literature
Author: Umar Ibrahim Gaya
Publisher: Springer Science & Business Media
ISBN: 9400777752
Category : Science
Languages : en
Pages : 222
Get Book Here
Book Description
This book underscores the essential principles of photocatalysis and provides an update on its scientific foundations, research advances, and current opinions, and interpretations. It consists of an introduction to the concepts that form the backbone of photocatalysis, from the principles of solid-state chemistry and physics to the role of reactive oxidizing species. Having recognised the organic link with chemical kinetics, part of the book describes kinetic concepts as they apply to photocatalysis. The dependence of rate on the reaction conditions and parameters is detailed, the retrospective and prospective aspects of the mechanism of photocatalysis are highlighted, and the adsorption models, photocatalytic rate expressions, and kinetic disguises are examined. This book also discusses the structure, property, and activity relationship of prototypical semiconductor photocatalysts and reviews how to extend their spectral absorption to the visible region to enable the effective use of visible solar spectrum. Lastly, it presents strategies for deriving substantially improved photoactivity from semiconductor materials to support the latest applications and potential trends.
