Bi2WO6 hierarchical microspheres assembled by nanosheets and dispersed nanosheets were synthesized by hydrothermal reaction in different conditions. Ag2O nanoparticles were deposited on the surface of Bi2WO6 microspheres and nanosheets by the chemical precipitation method. The photocatalytic performance of pure Bi2WO6 nanostructures and Ag2O/Bi2WO6 heterostructures were evaluated by the photocatalytic decolorization of RhB solution under visible-light irradiation. Compared with the pure Bi2WO6 nanostructures, the Ag2O/Bi2WO6 heterostructures exhibited an obviously enhanced photocatalytic activity. And photocatalytic activity of the Ag2O/Bi2WO6 microspheres is higher than that of the Ag2O/Bi2WO6 nanosheets. This work demonstrates that the Bi2WO6 hierarchical three-dimensional structure is an excellent architecture for the loading of Ag2O nanoparticles to build a highly efficient photocatalyst. (C) 2014 Elsevier B.V. All rights reserved.