Efficient visible-light active ZnO/Bi2MoO6/AgBr nanocomposites were fabricated using ultrasonic assisted method. Crystallinity, structural, morphological, optical, and textural features of the photo catalysts were investigated by XRD, SEM, TEM, EDX, FT-IR, IJV-Vis DRS, PL, and BET techniques. Photocatalytic performance of the ZnO sample was remarkably increased by combining with Bi2MoO6 and AgBr, due to formation of tandem n-n heterojunctions. The as-prepared ZnO/Bi2MoO6/AgBr nano composites exhibited excellent photocatalytic activity and stability under visible light in comparison with the ZnO, ZnO/Bi2MoO6, and ZnO/AgBr samples. About similar to 97% of RhB was removed in 70 min by the optimized ZnO/Bi2MoO6/AgBr (20%) nanocomposite, which is 76.4, 4.75, and 17.3 times as fast as the ZnO, ZnO/Bi2MoPO6 (20%) and ZnO/AgBr (20%) photocatalysts, respectively. It was confirmed that due to improved utilization of visible light, considerable separation of the charge carriers, and enlarged surface area, the ZnO/Bi2MoO6/AgBr (20%) nanocomposite exhibited greatly improved photocatalytic activity in degradations of various dye contaminants under visible-light illumination. In addition, plausible photocatalytic degradation mechanism for the highly enhanced performances were also proposed. (C) 2018 Elsevier B.V. All rights reserved.