Stabilization of ZnO Nanoparticles Using Water Extract of Waste Coconut Husk and Photocatalytic Activity

Abstract

Here, we report the synthesis of highly photoactive zinc oxide nanoparticles using water extract of waste coconut husk ash as a precipitating agent in a green approach which is a potential source of natural alkaline media. The formation of zinc oxide nanoparticles at different pH of the solution of coconut husk ash was confirmed through powder XRD, SEM-EDX, UV-Vis, FTIR and photoluminescence spectroscopy. The photocatalytic performance of the samples was evaluated through the degradation of methylene blue (MB)and methyl orange (MO) under solar irradiation which undergoes degradation around 98% and 56% within 120 min, respectively. The high photocatalytic activity and rate constant could be attributed to the large surface area due to small particle size that could provide quicker photon absorption and reduction of charge carrier recombination. This current work introduces a new method to reduce energy consumption for the synthesis of highly photoactive low-cost zinc oxide nanoparticles.