Plant extract mediated ZnO-NPs as photocatalyst for dye degradation: An overview

Abstract

Clean water is the basic need of all, it is impossible to imagine a future without it. However, the lack of a long-term water management plan and rapid industrialization resulted in the contamination of water sources to a dangerous extent. Excessive use of toxic textile dyes and their secretion in natural water resources is one of the major concerns for today's world. Photocatalysis is one of the best phenomena to resolve the issue of harmful textile dyes in the aquatic environment, where the photo-induced electron and hole pairs generated by excitation of electrons from the valence band to the conduction band by light irradiance can be used for the degradation of dye molecules through redox reactions. ZnO is a semiconductor material that shows excellent potential in photocatalysis. As the synthesis of biocompatible ZnO nanoparticles (NPs) using plant extract as biological reducing and capping agents is one of the best ways to have all the benefits of different physicochemical properties of nanomaterials without potential environmental and human health risks resulted from nanoparticles. Therefore, the use of green synthesized ZnO-NPs prepared using various parts of the plant in the degradation of harmful textile dyes has been explored by many researchers. In this article, we will provide an overview of the procedure to synthesize the biocompatible ZnO-NPs and their use in the photocatalytic degradation of dyes.