Influences of Graphene Nanosheets Coating on Selectively Exposed Crystal Facet ZnO

Graphene/ZnO composite attracting increasing attention due to great photoelectrochemical performance, however, graphene nanosheets tend to be coated on the one crystal plane of ZnO is rarely investigated. Herein, we synthesized different ZnO micro-nanoparticles with selectively exposed crystal facet through a hydrothermal process by controlled some parameters such as temperature, concentration of reagents and reaction time, and the corresponding RGO/ZnO composites were obtained. Characterization by SEM and TEM, it was first time demonstrate that graphene nanosheets were tend to be coated on the (100) and (002) crystal facets of ZnO micro-nanoparticles. We further discover that the largest exposed crystal facet of RGO/ZnO became (101) crystal plane. Regarding their performance in photocatalytic RhB degradation, exposed crystal facets of ZnO were found to impose crucial influence: the sample's photoelectrochemical properties are positively related to exposed degree of (101) facet, and it trend follows the order ZnO101 > RGO/ZnO101 > ZnO100 > RGO/ZnO100 > RGO/ZnO002 > ZnO002. Moreover, it can provide a new strategy that the films were coated on suitable crystal facet to change the photoelectrochemical properties of composite.