ZnO and Bi3+-doped ZnO photocatalysts with different molar ratio of Bi/Zn were prepared by a parallel flaw precipitation method. The photocatalysts prepared were characterized by BET surface area, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopic techniques (XPS), UV/Vis diffuse reflectance spectroscopy (DRS) and surface photovoltage spectroscopy (SPS), respectively. The results show that doping Bi into ZnO increases the BET surface area. The XRD spectra of the Bi3+-doped ZnO photocatalysts calcined at 573 K show only the characteristic peaks of wurtzite-type. Doping Bi3+ into ZnO influences the response to the light and the photoinduced charge separation rate, changes the morphology of ZnO and induces binding energy value of Zn2p(3/2) shift. The photocatalytic activity of Bi3+-doped ZnO photocatalysts for decolorization of methyl orange (MO) solution was evaluated, of all the photocatalysts prepared, the Bi3+-doped ZnO with 5% Bi possesses the best photocatalytic activity among the experimented compositions and the possible reason was discussed. (C) 2012 Elsevier B. V. All rights reserved.