AgBr/Ag2O heterostructure photocatalysts were synthesized by a simple in situ anion-exchange route. The ratio of AgBr and Ag2O in the composites could be easily controlled by adjusting the concentration of NaBr solution. The AgBr/Ag2O-5 heterostructure exhibited a much higher photocatalytic activity than the pure AgBr and Ag2O particles in photodegradation of methyl orange (MO) under visible light irradiation. On the basis of the characterization by X-ray diffraction, photoluminescence (XRD), X-ray photoelectron spectroscope (XPS), and UV-vis diffuse reflectance spectra (DRS), a mechanism was proposed to account for the enhanced photocatalytic activity of AgBr/Ag2O heterostructure. (C) 2015 Elsevier B.V. All rights reserved.