ZnO-rGO nanocomposite as high-performance photocatalyst in dye degradation

Abstract

The heterogeneous photocatalytic process has been considered as one of the most emerging methods for treatment of dye wastewater due to its cost-effectiveness, efficiency and stability. This study focuses on achieving excellent photocatalytic performance by dispersing Zinc oxide within the rGO sheets. In a two-step method, Zinc oxide-reduced graphene oxide (ZnO-rGO) composites were synthesized, initially KOH reacts with Zinc acetate in the aqueous dispersions of graphene oxide (GO) to form a Zn(OH)2/graphene oxide precursor, followed by thermal treatment follows.
It is found that the dispersion of Zinc oxide within the rGO sheets is a key for achieving an excellent catalytic performance of the samples. ZnO-rGO composite with suitable mass ratio achieved more photocatalytic activity than pure ZnO. ZnO s ability to accept electrons is promoted by the rGO support. As a result, enhancement in photocatalytic activity is obtained. The samples are characterized by XRD, SEM, EDAX and UV–VIS diffuse reflectance spectroscopy methods. The photocatalytic activity of ZnO-rGO has been examined by degradation of the Direct blue 199 dye wastewater. 99.6% of dye degradation was obtained using ZnO-rGO composites.