Graphene oxide/Ag3PO4 (GO-Ag3PO4) composite photocatalysts were prepared by a simple precipitant method. The obtained samples were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The photocatalytic activity was investigated by the degradation of MB. An increase in photocatalytic activity was observed for GO-Ag3PO4 composite materials compared with pure Ag3PO4 under visible light. This improvement was attributed to the following two reasons: increased migration efficiency of photo-induced electrons and increased adsorption activity for dye molecules. A study of the effect of the amount of GO on the photocatalytic activity showed that there was an optimum amount of 10%. (C) 2013 Elsevier B.V. All rights reserved.