TiO₂-based photocatalytic disinfection of microbes in aqueous media: A review

Laxma Reddy, P.Venkata,Kavitha, Beluri,Kumar Reddy, Police Anil,Kim, Ki-Hyun Academic Press 2017 Environmental research Vol.154 No.-

<P><B>Abstract</B></P> <P>The TiO<SUB>2</SUB> based photocatalyst has great potential for the disinfection/inactivation of harmful pathogens (such as <I>E.coli</I> in aqueous media) along with its well-known usefulness on various chemical pollutants. The disinfection property of TiO<SUB>2</SUB> is primarily attributed to surface generation of reactive oxygen species (ROS) as well as free metal ions formation. Furthermore, its disinfection capacity and overall performance can be significantly improved through modifications of the TiO<SUB>2</SUB> material. In this review, we provide a brief survey on the effect of various TiO<SUB>2</SUB> materials in the disinfection of a wide range of environmentally harmful microbial pathogens (<I>e.g</I>., bacteria, fungi, algae, and viruses) in aqueous media. The influencing factors (such as reactor design, water chemistry, and TiO<SUB>2</SUB> modifications) of such processes are discussed along with the mechanisms of such disinfection. It is believed that the combined application of disinfection and decontamination will greatly enhance the utilization of TiO<SUB>2</SUB> photocatalyst as a potential alternative to conventional methods of water purification.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The advent of industrialization jeopardized the quality of drinking water. </LI> <LI> TiO<SUB>2</SUB> photocatalysis holds promise both in the degradation of pollutants and for disinfection. </LI> <LI> The applicability of TiO<SUB>2</SUB>-based decontamination is explored for microbial disinfection. </LI> <LI> Here we provide a comprehensive review on titania-based photocatalysts for disinfection. </LI> </UL> </P>

Enhanced hydrogen production activity over BiO X TiO 2 under solar irradiation: Improved charge transfer through bismuth oxide clusters

Reddy, Police Anil Kumar,Manvitha, Chennaiahgari,Reddy, Pullagurala Venkata Laxma,Kim, Ki-Hyun,Kumari, Valluri Durga Elsevier Inc 2017 Journal of Energy Chemistry Vol.26 No.3

<P>A series of titania nanoparticles and nanotubes deposited with various quantities of bismuth (Bi) were prepared via sol-gel and hydrothermal methods, respectively. They were then characterized using X-ray diffraction spectroscopy (XRD), X-ray photo electron spectroscopy (XPS), UV-Vis diffused reflectance spectra (DRS), photoluminescence spectra (PLS), transmission electron microscopy (TEM), energy dispersive analysis of X-rays (EDAX), and BET surface analysis. These catalysts were employed for the photocatalytic production of hydrogen from a mixture of pure water and glycerol under solar light irradiation. The presence of the Bi(3 + x)+ species was found to play a vital role in enhancing activity while minimizing electron hole recombination (relative to bare TiO2). The nanotubes exhibited better activity than the nanoparticles of Bi-deposited TiO2, showing the significance of the morphology; however, photocatalytic activity is predominantly dependent on the deposition of bismuth. The activity increased by approximately an order of magnitude at the optimum concentration of Bi deposited over TiO2 (2 wt%). The presence of the Bi(3 + x)+ species played a vital role in minimizing electron hole recombination, resulting in higher activity compared to bare TiO2. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.</P>

Photocatalytic degradation of bisphenol A in aqueous media: A review

Reddy, P. Venkata Laxma,Kim, Ki-Hyun,Kavitha, Beluri,Kumar, Vanish,Raza, Nadeem,Kalagara, Sudhakar Elsevier 2018 Journal of environmental management Vol.213 No.-

<P><B>Abstract</B></P> <P>Bisphenol A (BPA) is known to be an emerging pollutant in various environmental compartments. Human exposure to BPA occurs widely because it is commonly used as the raw material in a variety of industrial processes (e.g., the preparation of epoxy and polycarbonate resins). In this review, a brief survey was carried out to cover a range of photocatalytic materials (e.g., titania, zinc, silver, carbon, and bismuth) and their modified forms as an effective means to treat water systems contaminated with BPA. The overall efficiency and limitations of these catalysts are described for the photocatalytic treatment of BPA.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bisphenol A [BPA] is a rapidly emerging pollutant in the ambient environment. </LI> <LI> BPA removal through application of photocatalysis has been explored intensively. </LI> <LI> Competence of Ti, Zn, Ag, Bi, and C-based photocatalysts are discussed. </LI> <LI> Combination of hydroxyl radical (OH) and photogenerated holes is crucial in BPA removal. </LI> </UL> </P>

A Review of Photocatalytic Treatment for Various Air Pollutants

Reddy, P. Venkata Laxma,Kim, Ki-Hyun,Kim, Yong-Hyun Korean Society for Atmospheric Environment 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.3

Photocatalysis is a photochemical catalytic reaction which is a highly promising tool for the environmental cleanup process. It is very effective in treatment of environmental pollutants by its unique redox property. It has wide applications in the treatment of atmospheric pollutants (e.g., nitrogen dioxide, trichloroethylene, volatile organics, hydrogen sulfide, benzene, etc) through oxidative removal and by disinfection (aeromicro flora). In this research, the fundamental aspects of photocatalysis are described with respect to the composition of catalysts, experimental conditions (e.g., temperature, duration, etc), and interfering factors (e.g., catalyst deactivation).

A Review of Photocatalytic Treatment for Various Air Pollutants

P. Venkata Laxma Reddy,Yong-Hyun Kim,김기현 한국대기환경학회 2011 Asian Journal of Atmospheric Environment (AJAE) Vol.5 No.3

Photocatalysis is a photochemical catalytic reaction which is a highly promising tool for the environmental cleanup process. It is very effective in treatment of environmental pollutants by its unique redox property. It has wide applications in the treatment of atmospheric pollutants (e.g., nitrogen dioxide, trichloroethylene,volatile organics, hydrogen sulfide, benzene,etc) through oxidative removal and by disinfection (aeromicro flora). In this research, the fundamental aspects of photocatalysis are described with respect to the composition of catalysts, experimental conditions (e.g., temperature, duration, etc), and interfering factors (e.g., catalyst deactivation).

Benefits and limitations of biochar amendment in agricultural soils: A review

Kavitha, Beluri,Reddy, Pullagurala Venkata Laxma,Kim, Bojeong,Lee, Sang Soo,Pandey, Sudhir Kumar,Kim, Ki-Hyun Elsevier 2018 Journal of environmental management Vol.227 No.-

<P>Current agriculture faces multiple challenges due to rapid increases in food demand and environmental concerns. Recently, biochar application in agricultural soils has attracted a good deal of attention. According to literature findings, biochar has proven to play various beneficial roles with respect to the enhancement of crop yield as a fertilizer and soil quality as a soil conditioner. It can further be used to remediate soil pollution as an adsorbent, while supporting the mitigation of greenhouse gases (GHGs) through the expansion of the soil carbon pool. The efficacy of biochar application on agricultural environments is found to be controlled by various factors such as pyrolysis temperature, feed stock, soil type, and biotic interactions. The combined effects of these factors may thus exert a decisive control on the overall outcome. Furthermore, the biochar application can also be proven to be detrimental in some scenarios. This review evaluates both the potential benefits and limitations of biochar application in agriculture soils.</P>

Novel approach for the synthesis of nitrogen-doped titania with variable phase composition and enhanced production of hydrogen under solar irradiation

안일쿠마레디,P. Venkata Laxma Reddy,김기현,만다리코테쉬쿠마,Chennaiahgari Manvitha,심재진 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.53 No.-

In order to maximize the photocatalytic production of hydrogen, it is desirable to develop an efficient photocatalyst with enhanced yield and visible sensitivity. To this end, we developed a novel method to synthesize nitrogen doped TiO2 with anatase/rutile/brookite mixed phases in aqueous urea solutions. The hydrogen production capacity of the nitrogen doped multiphase TiO2 (e.g., anatase (69%)/brookite (17%)/rutile (14%)), when assessed under solar light irradiation, was six times higher than that of commercial Degussa P25 and bare TiO2 catalysts. Such enhanced efficiency was ascribed to increased visible absorption along with effective electron–hole separation between the different crystalline phases.