Photocatalytic studies of Ag/ZnO nanocomposite particles produced via ultrasonic spray pyrolysis method

•Ag/ZnO nanocomposite catalyst with a single step route is synthesized.•Methylene Blue decolorization, degradation and first order kinetics is studied.•The highest decolorization and degradation rates are 40% and 27% respectively.•The highest degradation rate coefficient is 9×10−3min−1.•Crystallite sizes and atomic fraction difference are important parameters. Noble metal/semiconductor oxide nanocomposites have considerable interest on degradation of pollutants from textile wastewaters. Ag/ZnO, as one of the noble metal/semiconductor oxide nanocomposite, is highly efficient catalyst in textile pollutant degradation that allows irradiation wavelength towards visible light region. Ultrasonic spray pyrolysis method was used to produce spherical, homogenously distributed and submicron Ag/ZnO nanocomposite particles in one step. A water leach solution (0.05–0.2M, Ag+:Zn2+=1:1) is carried by non-cost air into the reaction furnace (T=700°C, 800°C and 900°C). UV-A illumination of Methylene Blue (MB) with the presence of Ag/ZnO nanocatalysts after 60min results up to 40% MB decolorization, 9×10−3 min−1 decolorization rate constant.