Performance Enhancement of ZnO Photocatalyst via Synergic Effect of Surface Oxygen Defect and Graphene Hybridization

Abstract

ZnO1-x/graphene hybrid photocatalyst was prepared via a facile in-situ reduction of graphene oxide and ZnO1-x surface defect oxide. The hybrid photocatlayst showed enhanced photocatalytic activity for the photodegradation of methylene blue. The photocorrosion of ZnO1-x was successfully inhibited by graphene hybridation. ZnO1-x/graphene hybrid photocatalyst with 1.2 wt % graphene showed the optimized photocatalytic activity. The photocatalytic activity of ZnO1-x/graphene-1.2 wt % under visible and UV light was about 4.6 and 1.2 times that of ZnO1-x sample, respectively. The photocurrent intensity of ZnO1-x under visible and UV light irradiation can be enhanced by 2 and 3.5 times by graphene hybridization. The enhancement of photocatalytic activity and photocurrent intensity in ZnO1-x/graphene was attributed to the synergistic effect between graphene and ZnO1-x for high separation efficiency of photoinduced electron-hole pairs mainly resulting from the promotion of HOMO orbit of graphene and the Oi″ defect level of ZnO1-x in ZnO1-x/graphene.