In the present study, nano-structured ZnO and Sn-doped ZnO photocatalysts with high sunlight photocatalytic activity were successfully synthesized through the decomposition of zinc acetate and glucose by microwave heating. The prepared ZnO and Sn-doped ZnO photocatalyst were characterized by Xray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectrum (PL), UV-vis absorption spectrum (UV-vis), N-2 adsorption and UV-vis diffuse reflectance spectra (DRS). The results showed that the doping greatly changed the microstructure, morphology and optical properties of ZnO, which may contribute to the enhancement of photocatalytic activity. The sunlight photocatalytic activity of the prepared pure ZnO and Sn-doped ZnO photocatalyst was investigated by the degradation of Methylene Blue (MB) solution under sunlight irradiation. Compared with pure ZnO, 13% higher decolorization rate and 29-52% higher mineralization efficiency were obtained by the Sn-doped ZnO. The results indicated that Sn-doped ZnO had a higher photocatalytic activity and Sn dopant greatly increased the photocatalytic activity of ZnO. (C) 2010 Elsevier B.V. All rights reserved.