BACKGROUND: Plasmonic photocatalysts have attracted considerable attention because of their applications in the degradation of organic pollutants. In order to enhance the stability of AgX photocatalyst, Ag/AgCl, Ag/AgBr/WO3, and Ag@AgCl/RGO were developed. Results implied that silver halides could maintain stability if the metal Ag was well dispersed on the silver halide particles and could display high catalytic activity. RESULTS: PVP acted as a structure-directing agent, and a reducing reagent in the reaction. Results show that AgAgBr delivered a much higher photocatalytic activity than AgBr and AgAgCl. The high photocatalytic activity of the AgAgBr composites can be attributed to the presence of metal Ag and the smaller particle size of the samples. The photocatalytic reaction followed first-order kinetics. The rate constant k for the degradation of MO by AgAgBr was 2 and 18 times higher than that of AgBr and AgAgCl, respectively. CONCLUSIONS: The MO degradation efficiency of AgAgBr was 94% after 10 min. After 5 cycles of repeatability tests, the degradation efficiency of MO still remained at 90%. The high photocatalytic activity of the AgAgBr composites can be attributed to the presence of metal Ag and the smaller particle size of the samples. Copyright (c) 2012 Society of Chemical Industry