A facile one-pot method for the fabrication of high quality self-assembled hierarchically ordered macro-mesoporous ZnS microsphere-reduced graphene oxide (RGO) composite without the use of templates or surfactants is described. During the hydrothermal process, reduced graphene oxide (RGO) was loaded into the ZnS microsphere by in situ reduction of graphene oxide added in the self-assembly system. The morphology and structure of the as-prepared composites were confirmed by X-ray diffraction, high resolution transmission electron microscopy, energy dispersive X-ray analysis, Fourier transform infrared spectroscopy and Raman spectroscopy. Incorporation of reduced graphene oxide as an excellent electron-transporting material effectively suppresses the charge recombination. Hence, a significant enhancement in the photocatalytic efficiency for the photodegradation of methylene blue was observed with the ZnS-RGO composite, compared to the pure ZnS. Overall, this research results may lay down new vistas for the in situ fabrication of the ZnS-RGO composite as a highly efficient photocatalysis under visible-light irradiation and their applications in environmental protection. (c) 2013 Elsevier B.V. All rights reserved.