Faculty Publications
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Item Photocatalytic degradation of p-nitrophenol using biologically synthesized ZnO nanoparticles(Springer Science and Business Media Deutschland GmbH, 2021) Kadam, V.V.; Shanmugam, S.D.; JagadeeshBabu, J.; Mohan Balakrishnan, R.M.The present work deals with the photocatalytic degradation of p-nitrophenol as it is a United States Environmental Protection Agency-listed priority pollutant and has adverse environmental and health effects. To eradicate the detrimental environmental impact of p-nitrophenol, the biologically synthesized ZnO nanoparticles were used as a photocatalyst. The degradation of p-nitrophenol was confirmed by decreasing the absorbance value at a characteristic wavelength of 317 nm using the UV-vis spectrophotometer. Reaction parameters such as ZnO photocatalyst concentration of 0.1 g/L at pH 11 in the presence of H2O2 (5 mM) were found to be optimum conditions for p-nitrophenol degradation. The photocatalytic degradation was slowly enhanced in the presence of H2O2 as an electron acceptor. The kinetics of nitrophenol degradation was studied, which follows the pseudo-first-order reaction. The photocatalytic degradation of p-nitrophenol was characterized by using total organic carbon, chemical oxygen demand, and high-performance liquid chromatography analyses. This method is found to be effective as it is environmentally friendly, free of toxic chemicals. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.Item Photocatalytic degradation of diclofenac using TiO2-CdS heterojunction catalysts under visible light irradiation(Springer Science and Business Media Deutschland GmbH, 2021) Mugunthan, M.; Bharathaiyengar, S.M.; JagadeeshBabu, J.The present study reports the photocatalytic degradation of analgesic drug diclofenac using the hydrothermally prepared TiO2-CdS heterojunction catalyst. The results suggest that the prepared catalysts exhibited excellent photocatalytic activity under visible light irradiation. The photodegradation kinetics were well fitted to the pseudo-first-order reaction. The apparent reaction rate constant for TC5 catalyst in the diclofenac degradation was 0.02316 min?1. Mineralisation of diclofenac using TC5 photocatalyst was around 86% within 4 h of irradiation time. The operating parameters such as optimal catalyst dosage, apparent solution pH and the effect of initial diclofenac concentration were also studied using the TC5 catalyst. The role of active species in the degradation mechanism was elucidated and it was found that the hydroxyl radical is the main active species in the diclofenac degradation mechanism. The charge transfer between heterojunction catalysts is facilitated by direct Z-scheme heterojunction structure. The coupled photocatalysts also showed good photochemical stability and reusability over five successive reaction cycles. The tentative degradation pathway has been devised based on LC-MS peaks, and it is found that only m/z 224, m/z 178 and m/z 124 were persisted at the end of the reaction. © 2021, Springer-Verlag GmbH Germany, part of Springer Nature.Item TiO2-WO3 nanocube-polyaniline hierarchical membrane for efficient removal of chromium in a photocatalytic membrane reactor(John Wiley and Sons Inc, 2023) Rathna, T.; JagadeeshBabu, J.; Ruben Sudhakar, D.R.In this article, the rational design of a physically coated TiO2-WO3 nanocube-polyaniline photocatalytic membrane (hierarchical) reactor for the efficient reduction of chromium (VI) under visible light is discussed. The incorporation of TiO2-WO3 in the polyaniline (PANI) membrane provides excellent hydrophilicity and high photo-corrosion resistance and facilitates the rapid permeation of water with a flux rate of 12 L/m2 h and higher Cr (VI) reduction. The exposure of bare PANI membranes in Cr (VI) solution leads to over-oxidation of PANI membrane and eventually leads to the destruction of the membrane. The hierarchical photocatalytic coating improves the lifetime of the membrane by blocking it from deprotonation. The photocatalytic membrane could offer 79.30% Cr (VI) reduction under visible light irradiation in a photocatalytic membrane reactor. After several reduction cycles, the membrane showed good self-cleaning ability. The present work suggests that TiO2-WO3 nanocube-coated PANI hierarchical membrane is a promising approach for the reduction and removal of Cr (VI) from wastewater. © 2023 CIWEM.