Biosynthesized Selenium co-catalyst for Improved Photocatalytic activity of Se-ZnO Nanocomposites.

Abstract

The present study deals with the biosynthesis of selenium nanoparticles and their impregnation as co-catalyst on ZnO semiconductor. The synthesized catalyst was characterized for its physicochemical properties using UV-DRS, DLS, TEM, SEM-EDS and XRD. The potential of biosynthesized catalyst was tested against the photocatalytic degradation of recalcitrant compound 4-chloroguaiacol and real pharmaceutical industry effluent. Various concentrations of Se were doped on ZnO semiconductor and 0.5wt% was found to be the most optimum. Effect of Photocatalyst on different concentrations of the model compound was also evaluated. Photocatalytic reactions were carried out using solar radiations to make the process cost-effective. Kinetic study of degradation reaction was performed and it was observed to follow first-order reaction kinetics. Complete mineralization of the model compound was confirmed when 88% of CO2 evolution was observed at the completion of the reaction. The potential of biosynthesized catalyst was also assessed against the treatment of real pharmaceutical industrial effluent and significant COD reduction of 50% was observed.