Reduced Graphene Oxide-Hierarchical ZnO Hollow Sphere Composites with Enhanced Photocurrent and Photocatalytic Activity

The reduced graphene oxide (RGO)-hierarchical ZnO hollow sphere composites are prepared through a simple ultrasonic treatment of the solution containing graphene oxide (GO), Zn(CH 3 COO) 2, DMSO, and H 2 O. The GO is reduced to RGO effectively, and the ZnO hollow spheres consisting of nanoparticles are uniformly dispersed on the surface of RGO sheets during the ultrasonic process. The optimum synergetic effect of RGO-ZnO composites is found at a RGO mass ratio of 3.56%, and the photocurrent and photodegradation efficiency on methylene blue of RGO-ZnO composites are improved by five times and 67%, respectively, compared with those of pure ZnO hollow spheres. The enhancements of photocurrent and photocatalytic activity can be attributed to the suppression of charge carriers recombination resulting from the interaction between ZnO and RGO.