A novel AgBr/WO3 composite photocatalyst was synthesized by loading AgBr on WO3 substrate via deposition-precipitation method and characterized by XRD, SEM and DRS. The as-prepared AgBr/WO3 was composed of monoclinic WO3 substrate and face-centered cubic AgBr nanoparticles with crystalline sizes less than 56.8 nm. AgBr/WO3 had absorption edge at about 470 nm in the visible light region. The optical AgBr content in AgBr/WO3 was 0.30:1 (Ag/W) at the corresponding apparent rate, k(app), of 0.0160 min(-1) for MO degradation. The highest k(app) was 0.0216 min(-1) for 4 g/L catalyst. The (OH)-O-center dot acted as active species. Addition of H2O2 within 0.020 mmol/L can efficiently trap electrons to generate more (OH)-O-center dot and further improved photocatalytic activity of AgBr/WO3. (C) 2011 Elsevier B.V. All rights reserved.