Flower-like Bi2WO6 and Bi2O3-Bi2WO6 composite microstructures have been synthesized via a facile and rapid microwave-assisted hydrothermal method through controlling the experimental parameters. The phases and morphologies of the products are characterized by powder X-ray diffraction (XRD), energy dispersion X-ray analysis (EDX), high resolution transmission electron microscopy (HRTEM), and scanning electron microscopy (SEM). Photocatalytic experiments indicate that such Bi2O3-Bi2WO6 composite possesses higher photocatalytic activity for RhB degradation under visible-light irradiation in comparison with pure Bi2O3 and Bi2WO6. On the basis of the calculated energy band positions, the enhanced photocatalytic activity is attributed to the effective separation of electron-hole pairs between the two semiconductors. The present study provides a new strategy to design composite materials with enhanced photocatalytic activity. (C) 2012 Elsevier Inc. All rights reserved.