Photocatalytic degradation of malachite green dye by plant-mediated biosynthesized zinc oxide nanoparticles

Abstract

Photocatalytic activity of ZnO-NPs was tested by degradation of Malachite Green dye under UV light irradiation. The ZnO-NPs were biosynthesized using Punica granatum (pomegranate) fruit peels extract as the stabilizing agent. Simple sol-gel method and calcination in different temperatures (400, 500, 600 and 700°C) were carried out to obtain pure ZnO-NPs with high photocatalytic properties. In the degradation studies, 20 mg ZnO-NPs were used to degrade Malachite Green dye of 10 ppm initial concentration for a total period of 50 minutes in a 100 ml reaction volume. Results obtained shown that ZnO-NPs calcined in 700°C had the highest removal efficiency at about 99% in 40 minutes. This proves that biosynthesized ZnO-NPs have a high potential to be used as a photocatalyst to degrade textile dyes in a short time for wastewater treatments.