ZnO disks loaded with reduced graphene oxide for the photodegradation of methylene blue

Graphene oxide was loaded onto ZnO disks with dominant polar facets and photo-reduced to form ZnO-RGO photocatalysts. Their photocatalytic activity for methylene blue degradation is remarkably improved under UV–visible light irradiation. The enhanced activity is ascribed to the trapping effect of RGO for photoexcited electrons that inhibits electron/hole recombination and to the adsorption effect of RGO for methylene blue to increase its local concentration. The optimal loading of the RGO is ca. 2 mass%, above which light absorption by the RGO decreases the photo utilization efficiency. Carbon Materials 2013, 28(6): 408–413]