Author
A. Stephen
Bio: A. Stephen is an academic researcher from University of Madras. The author has contributed to research in topics: Photocatalysis & Methyl orange. The author has an hindex of 21, co-authored 23 publications receiving 4789 citations.
Topics: Photocatalysis, Methyl orange, Nanocomposite, Visible spectrum, Nanorod
Papers
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TL;DR: The photocatalytic degradation of organic dyes such as methylene blue and methyl orange in the presence of various percentages of composite catalyst under visible light irradiation was carried out by new thermal decomposition method, which is simple and cost effective.
911 citations
TL;DR: Results showed that the Ag nanoparticles induced visible light activity and facilitated efficient charge separation in the ZnO/Ag/CdO nanocomposite, thereby improving the photocatalytic performance.
574 citations
TL;DR: In this study, the catalysts were prepared by thermal decomposition method, which was employed for the first time in the preparation of ZnO/Ag nanocomposite catalysts, and results suggest better photocatalytic properties for 10 wt.% Ag sample compared to other samples.
525 citations
TL;DR: In this paper, a nanorod of pure ZnO was synthesized by simple thermal decomposition method using direct calcination of zinc acetate dihydrate, which was confirmed by X-ray diffraction.
450 citations
TL;DR: The photocatalytic activities of prepared catalysts were evaluated using the degradation of aqueous methylene blue solution as a model compound under visible light irradiation and results suggested that the prepared CeO 2/V2O5 and CeO2/CuO nanocomposites can generate more electrons and holes under visibleLight irradiation.
445 citations
Cited by
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TL;DR: This paper presents a critical review of recent achievements in the modification of ZnO photocatalyst for organic contaminants degradation and recommends improvements in the heterogeneous photocatalysis under UV/visible/solar illumination.
1,646 citations
TL;DR: The different types of materials used as delivery vehicles for chemotherapeutic agents and their structural characteristics that improve the therapeutic efficacy of their drugs are discussed and recent scientific advances in the area of chemotherapy are described.
Abstract: Although conventional chemotherapy has been successful to some extent, the main drawbacks of chemotherapy are its poor bioavailability, high-dose requirements, adverse side effects, low therapeutic indices, development of multiple drug resistance, and non-specific targeting. The main aim in the development of drug delivery vehicles is to successfully address these delivery-related problems and carry drugs to the desired sites of therapeutic action while reducing adverse side effects. In this review, we will discuss the different types of materials used as delivery vehicles for chemotherapeutic agents and their structural characteristics that improve the therapeutic efficacy of their drugs and will describe recent scientific advances in the area of chemotherapy, emphasizing challenges in cancer treatments.
1,229 citations
TL;DR: The photocatalytic degradation of organic dyes such as methylene blue and methyl orange in the presence of various percentages of composite catalyst under visible light irradiation was carried out by new thermal decomposition method, which is simple and cost effective.
911 citations
TL;DR: The fabrication of different aspect ratios of the ZnO nanorods with surface defects by mechanical-assisted thermal decomposition method revealed that Zn O nanorod with higher aspect ratio and surface defects show significantly higher photocatalytic performances.
Abstract: ZnO, aside from TiO2, has been considered as a promising material for purification and disinfection of water and air, and remediation of hazardous waste, owing to its high activity, environment-friendly feature and lower cost. However, their poor visible light utilization greatly limited their practical applications. Herein, we demonstrate the fabrication of different aspect ratios of the ZnO nanorods with surface defects by mechanical-assisted thermal decomposition method. The experiments revealed that ZnO nanorods with higher aspect ratio and surface defects show significantly higher photocatalytic performances.
824 citations
TL;DR: It has been demonstrated that Ag NPs arrest the growth and multiplication of many bacteria such as Bacillus cereus, Staphylococcus aureus, Citrobacter koseri, Salmonella typhii, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Vibrio parahaemolyticus and fungus.
Abstract: Use of silver and silver salts is as old as human civilization but the fabrication of silver nanoparticles (Ag NPs) has only recently been recognized. They have been specifically used in agriculture and medicine as antibacterial, antifungal and antioxidants. It has been demonstrated that Ag NPs arrest the growth and multiplication of many bacteria such as Bacillus cereus, Staphylococcus aureus, Citrobacter koseri, Salmonella typhii, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumonia, Vibrio parahaemolyticus and fungus Candida albicans by binding Ag/Ag+ with the biomolecules present in the microbial cells. It has been suggested that Ag NPs produce reactive oxygen species and free radicals which cause apoptosis leading to cell death preventing their replication. Since Ag NPs are smaller than the microorganisms, they diffuse into cell and rupture the cell wall which has been shown from SEM and TEM images of the suspension containing nanoparticles and pathogens. It has also been shown that smaller nanoparticles are more toxic than the bigger ones. Ag NPs are also used in packaging to prevent damage of food products by pathogens. The toxicity of Ag NPs is dependent on the size, concentration, pH of the medium and exposure time to pathogens.
766 citations