Synthesis of bioinspired hierarchical Zinc Oxide for application as photocatalyst in wastewater treatment

Abstract

Bioinspired hierarchical zinc oxide photocatalyst was prepared by using luffa cylindrica (LC) as biotemplate via sol-gel and simple hydrothermal synthesis method. The physicchemical properties of the synthesized ZnO powders were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that ZnO synthesized by different methods inherited the structure of luffa cylindrica (LC). Besides that, the degradation of Reactive Green 19 under solar light irradiation was investigated to evaluate the photocatalytic activity of synthesized ZnO. The various parameters that can affect the photodegradation of RG 19 such as initial dye concentration, catalyst loading, effect of solar irradiation, and pH of the medium were investigated. Luffa-templated ZnO synthesized via sol-gel method shows the highest photocatalytic performance. The decrease in chemical oxygen demand (COD) and changes in UV-vis spectrum were monitored to investigate the photocatalytic mineralization. Around 84% COD removal was achieved under optimal conditions at the irradiation time of 6 hours.