This work reports novel ternary nanocomposites consisting of ZnO, Ag3VO4, and AgI as visible-light-driven photocatalysts with highly enhanced activity. The resultant samples were characterized using XRD, EDX, SEM, TEM, UV-vis DRS, FT-IR, BET, and PL techniques to reveal their microstructure, purity, morphology, texture, and spectroscopic properties. Photocatalytic activity of the samples was evaluated by degradation of rhodamine B (RhB) and methylene blue (MB) under visible-light irradiation. The effect of silver iodide weight percent, preparation time, and calcination temperature on the degradation reaction was investigated and the optimized values were obtained. Among the prepared samples, the ZnO/Ag3VO4/AgI (10%) nanocomposite exhibited the superior activity, which is about 5.1 and 3.6-fold higher than those of the ZnO/Ag3VO4 in degradations of RhB and MB, respectively. The enhanced activity was mainly attributed to reduction of electron-hole recombination, due to the formation of tandem n-n heterojunctions in the nanocomposite. Finally, it was revealed that superoxide ions are the predominant reactive species in the degradation reaction. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.