Au-deposited CeO2 (Au-CeO2) catalyst was prepared with a photo-reduction method and characterized by powder XRD (X-ray diffraction), TEM (transmission electron microscopy) and N-2 isothermal adsorption measurements. Degradation of acid orange 7 (AO7) was employed to evaluate the catalytic activity of Au-CeO2 in the presence of H2O2 either in dark or under the visible irradiation. The Au-CeO2 exhibits an obviously enhanced catalytic activity in the Fenton-like and photo Fenton-like degradation of AOP7 in pre-adsorbed mode (AO7 pre-adsorbed on CeO2 before the addition of H2O2) as well as in pre-mixed mode (CeO2 pre-mixed with H2O2 before the addition of AO7) and showed the highest catalytic activity at Au/Ce = 1.0%. Particularly, the chemical passivation from the surface over-complexation of H2O2 was significantly inhibited with the deposited Au clusters in pre-mixed mode. XPS (X-ray photoelectron spectroscopy), Raman and EPR (electron paramagnetic resonance) analyses show that the deposited Au clusters play an important role on increasing the concentration of Ce3+ in the CeO2. 1.0 at.% Au-CeO2 exhibits highest catalytic activity either in dark or under visible irradiation, which should be ascribed to its relative higher Ce3+ concentration. (C) 2013 Elsevier B.V. All rights reserved.