ZnO-TiO2-reduced graphene oxide (RGO) composites were successfully synthesized by microwave-assisted reduction of graphite oxide in ZnO precursor solution with TiO2 suspension using a microwave synthesis system. Their morphology, structure, and photocatalytic performance in the reduction of Cr(VI) were characterized by scanning electron microscopy, X-ray diffraction spectroscopy, and UV-vis absorption spectrophotometer. The results show that ZnO-TiO2-RGO composites exhibit an enhanced photocatalytic performance in reduction of Cr(VI) with a maximum removal rate of 99.4% under UV light irradiation as compared with pure ZnO (58%) and ZnO-RGO (98%) composites due to the increased light absorption intensity and the reduction of electron-hole pair recombination in ZnO with the introduction of TiO2. (C) 2012 Elsevier Inc. All rights reserved.