Interface coupling of octahedron Cu2O with reduced graphene oxide for enhanced photocatalytic and photoelectrochemical activity

Graphene oxide (GO) has been recognized as an ideal substrate material of semiconductor photocatalysts to achieve superior properties. Herein, Cu2O/reduced graphene oxide hetero-structures (Cu2O/rGO), featured by octahedron Cu2O with highly exposed {111} facets in-situ anchored on the framework of rGO nanosheets, were constructed via a green wet chemistry route at room temperature. During the reactions, Cu2+ ions that were adsorbed on GO could act as the nucleation sites of Cu2O while GO was further converted into rGO under the reduction of glucose, forming a robust hetero-interface of C–O–Cu bonding. Owning to the improved photon capture ability and carrier separation efficiency, the optimized Cu2O/rGO exhibits about 3.5 and 9.3 times enhancement of photocurrent intensity and photocatalytic activity, respectively, as compared to those of pure Cu2O. Meanwhile, the correlation among rGO content, structure and photocatalytic activity of Cu2O/rGO was demonstrated. This work presents a rational route and deep insight for the interface coupling within metal oxide/carbon material hetero-structures for advanced catalytic applications.