Photocatalytic Activity and Antibacterial Properties of Ag/N-doped TiO2 Nanoparticles on PVAE-CS Nanofibre Support PDF Download
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Author: Atsile Rosy Ocwelwang
Publisher:
ISBN:
Category : Chitosan
Languages : en
Pages : 190
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Author: Atsile Rosy Ocwelwang
Publisher:
ISBN:
Category : Chitosan
Languages : en
Pages : 190
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Author: Anibal Maury-Ramirez
Publisher: MDPI
ISBN: 3038421383
Category : Science
Languages : en
Pages : 213
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Book Description
This book is a printed edition of the Special Issue "Photocalytic Coatings for Air-Purifying, Self-Cleaning and Antimicrobial Properties" that was published in Coatings.
Author: Kranthi Kumar Akurati
Publisher: Cuvillier Verlag
ISBN: 3867277621
Category : Nanotechnology
Languages : en
Pages : 195
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Author: Koosha Azhie
Publisher:
ISBN:
Category :
Languages : en
Pages : 224
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While temporary disinfection of a surface is possible with the help of strong cleaners, tremendous interest exists for the control of microorganisms on surfaces by effective, durable antimicrobial coatings. There is a wide spectrum of potential applications for antibacterial coatings, spanning from industrial surface coatings to biomedical applications, where sterile conditions are crucial. This work examined the synthesis of the functionalized 2,2-Dimethylolpropionic acid - nanotitanium dioxide (DMPA-nTiO2) monomer. Moreover, functionalized nanotitanium dioxide/polyurethane (nTiO2/PU) composite coatings were prepared using the above mentioned functionalized monomer. The distribution of nTiO2 in the polymer matrix was enhanced by monomer functionalization in which nTiO2 was chemically attached to the backbone of the polyurethane polymer matrix with a bifunctional monomer (DMPA). The coordination of nTiO2 to DMPA was monitored by TGA characterization. Moreover, the surface hydrophilicity test was conducted on the nanofilms by examining the contact angle. SEM and elemental mapping analysis were also performed to study the surface morphology of the nanofilms and to measure the dispersion and compositional analysis of nanofillers in the polymer matrix. Two metal doped TiO2 nanoparticles (Fe/TiO2, and Ag/TiO2) were synthesized to control the band gap energy of TiO2 nanomaterials and hence the photocatalytic activities of nTiO2/polyurethane nanocomposite coatings. Moreover, some characterization techniques (such as SEM, TEM, XRD, and TGA) were done to probe the internal structure and properties of the above mentioned doped titania nanoparticles. The photocatalytic reaction rate constants of Fe and Ag doped TiO2 nanoparticles, along with undoped TiO2 nanoparticles, were measured and compared under solar light illumination. Since the photocatalytic reaction rate constant of Ag doped TiO2 nanoparticles was generally higher than that of Fe doped TiO2 nanoparticles, under both solar and visible light illumination, Ag doped TiO2 nanoparticles were used in this study to make functional nanocomposites. The antibacterial behavior of nTiO2/PU and silver doped nTiO2/PU composites were investigated qualitatively and quantitatively against both gram-negative (Escherichia coli) and gram-positive (Micrococcus luteus) bacteria. The effect of exposure time was investigated using a solar simulator by monitoring the growth of bacterial populations in the presence and absence of the above-mentioned nanocomposites. The quantitative examination of bacterial activity was determined by the survival ratio as calculated from the number of viable cells, which form colonies on the Petri dishes with nutrient agar. Excellent inhibition results were observed and demonstrated visually with more than 99% of bacteria killed after 2 hours of irradiation. In summary, the functionalized nTiO2/PU and silver doped nTiO2/PU composite coatings displayed considerable antibacterial activity against both gram-positive and gram-negative bacteria under solar light irradiation while silver doped nTiO2/PU coatings displayed considerable antibacterial activity even under irradiation of visible light.
Author:
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ISBN:
Category :
Languages : en
Pages :
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BackgroundTitanium dioxide (TiO2) on the implant surface plays an important role in osseointegration. TiO2 exerts a relatively high photocatalytic activity that generates reactive oxygen species (ROS) under ultraviolet irradiation. In contrast, nitrogen (N)-doped TiO2 exhibits photocatalytic activity under visible light irradiation. We previously evaluated the visible light-induced antimicrobial activity and biocalcification ability of N-doped TiO2.Aim/HypothesisThe aim of this study was to investigate the antimicrobial activity of N-doped TiO2 under visible light irradiation, and to evaluate the generation of ROS using electron spin resonance (ESR) spectrometry.Materials and MethodsTo prepare the N-doped TiO2, commercial pure titanium plates were soaked in NaOH solution and hot water, heated to 500u00b0C in an electric furnace in the presence of ammonia gas, and maintained at this temperature for 3 hours. Pure titanium substrates without surface modification were used as control samples. The visible light-induced antimicrobial effect of the sample against Escherichia coli JCM 5491 was evaluated using new test methods developed in accordance with the criteria of the JIS. A drop of bacterial suspension containing approximately 1.0 u00d7 10^6 CFU/mL was applied to each sample, and an adhesive film was placed on top. Each sample was irradiated with a 400u2013700 nm wavelength LED light for 15 minutes from a distance of 2 cm. After irradiation, the surviving bacteria were recovered with SCDLP medium, incubated for 48 hours on nutrient agar medium, and counted. Generation of ROS was determined using an ESR spin-trapping technique.ResultatsThe N-doped TiO2 had significantly superior antimicrobial activity in the presence of visible light against E. coli compared with the control samples (p
Author: Taicheng An
Publisher: Springer
ISBN: 3662534967
Category : Science
Languages : en
Pages : 321
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Book Description
This book presents the latest results related to photocatalytic inactivation/killing of microorganisms, which is a promising alternative disinfection method that produces less or even no disinfection byproduct. The book is divided into 13 chapters, which introduce readers to the latest developments in the photocatalytic disinfection of microorganisms, examine essential photocatalytic (PC) and photoelectrocatalytic (PEC) disinfection studies, and forecast and make recommendations for the further development of PC and PEC disinfection. Bringing together contributions by various leading research groups worldwide, it offers a valuable resource for researchers and the industry alike, as well as the general public. Taicheng An, PhD, is Chair Professor and Director at the Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou, China. Huijun Zhao, PhD, is Chair Professor and Director at the Centre for Clean Environment and Energy & Griffith School of Environment, Griffith University, Australia. Po Keung Wong, PhD, is a Professor at the School of Life Sciences, the Chinese University of Hong Kong, Hong Kong SAR, China.
Author: Mohamed A. Barakat
Publisher: Springer
ISBN: 3319242717
Category : Science
Languages : en
Pages : 39
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Book Description
In this brief, a comprehensive review of the UV/visible-TiO2 photocatalytic oxidation process is presented with an insight into the mechanisms involved, the role of titanium dioxide as a catalyst, irradiation sources, types of reactors, and a comparison between various modes of TiO2 application. An overview of the development and enhancement of the activity of TiO2 nanoparticles in photocatalysis is presented. The topics covered include a detailed look at the unique properties of the TiO2 nanoparticles and their relationship to photocatalytic properties. The utilization of the TiO2 nanoparticles as photocatalysts, in the non-doped and doped forms is also reviewed. Finally, the use of modified TiO2 nanoparticles has made a significant contribution in providing definitive mechanistic information regarding the visible light photocatalytic processes.
Author: Naizhen Yu
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Organic pollutants and pathogenic microbes exist in water systems causing many communities, especially in developing countries, to have a high risk of infection with water-borne diseases. Developing a simple, cost-effective, and efficient sunlight-driven water treatment technology is crucial for people to access clean and safe water. The most widely studied photoactive and antibacterial material is titanium dioxide (TiO2) nanoparticles (NPs). TiO2 NPs can produce highly reactive free radicals to oxidize organic pollutants and deactivate biological pollutants. However, pristine TiO2 NPs have a large band gap and only harvest solar radiation in the UV region. This thesis focuses on developing copper-doped titanium dioxide (TiCuxO2) catalysts and exploring its photocatalytic activity in the visible-light region. The first project focuses on synthesizing Cu-doped white TiO2 (wTiCuxO2) NPs using the solvothermal approach. The second project is a comprehensive study on Cu-doped black TiO2 (bTiCuxO2) NPs. The photocatalytic performance of the resulting TiCuxO2 catalysts (white and black particles) were evaluated using degradation of Rhodamine B (RhB) dye and disinfection of Escherichia coli (E. coli) under visible light irradiation. We show that introducing a Cu dopant and surface defects on the catalysts enhances its photodegradation ability. The mechanism of increased photocatalytic activity for TiCuxO2 is hypothesized to be due to band gap narrowing and accelerated charge separation. For disinfection ability, the activity might be related to the free Cu ions increasing the radical species under irradiation. In the project, I have developed two efficient photocatalysts for water treatment; the mechanistic studies of the nano-catalysts increase our understanding of the heterogeneous catalysts for photo-degradation of industrial dyes and inactivation of waterborne microbes, which are useful for engineering more efficient and sustainable water treatment devices.
Author: Vincenzo Augugliaro
Publisher: Royal Society of Chemistry
ISBN: 1847558704
Category : Science
Languages : en
Pages : 259
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Book Description
The book deals with the environmentally friendly cleaning materials functionalized with TiO2, a widely known semiconductor giving rise to redox reactions under artificial or solar irradiation. The role of titanium dioxide in the worldwide community is introduced first. The fundamental working principles of heterogeneous photocatalysis follow and a critical section on the semiconductor bulk and surface properties open the way to the differences between TiO2 blend features with respect to analogous thin film layouts. Then Follows the main section of the book which deals with the techniques applied to manufactured commercial devices, ranging from glasses to textiles and from concrete and other construction materials to paintings. Also road asphalt and other devices, such as photocatalytic air conditioning machines are outlined. Last generation materials, not yet commercialized, and the deposition techniques applied to prepare them are also widely discussed. The final part of the book covers the difficult and modern topic of standardization and comparison of performance of photocatalytic processes and in particular the guidelines proposed by various worldwide organizations for standardization are discussed. The book covers the general matters as well as the practical applications with the supporting methods discussed in detail. This book brings together a team of highly experienced and well-published experts in the field, providing a comprehensive view of the applications of supported titanium dioxide.
Author: Mohammad Ali Pelaschi
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
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.
