The surface of alpha-Bi2O3 was modified by either impregnating Zn acetate or coating with a sol-gel containing Zn hydroxide. The surface modified Bi2O3 powders were evaluated by UV-Visible spectroscopy, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and surface area analysis (BET). The photocatalytic performances were evaluated for the degradation of phenol, methylene blue and methyl orange. The variations in photocatalytic activity were correlated with morphology change. The presence of ZnO does not significantly prevent the progressive formation of photocatalytically inactive (BiO)(2)CO3, while the dye decolourization capability of nanocomposite is significantly preserved with respect to that of bare Bi2O3. (C) 2009 Elsevier B. V. All rights reserved.