Herein, we report the synthesis, characterization and visible-light driven photocatalytic degradation of Ag2O-decorated ZnO nanorods heterostructures. The Ag2O-decorated ZnO nanorods heterostructures were synthesized by ultrasonic-assisted precipitation method and characterized in detail which confirmed that the Ag2O nanoparticles were successfully decorated on the surfaces of ZnO nanorods heterostructures. Further, the synthesized heterostructures were used as efficient photocatalyst for the photocatalytic degradation of harmful dye, i.e. Amaranth dye, under visible light irradiation. The detailed photocatalytic experiments revealed that the synthesized heterostructures exhibited very high photocatalytic performance (similar to 94%) just in 30 min under visible light irradiation which was better than bare ZnO nanorods and Ag2O nanoparticles. The Ag2O-decorated ZnO heterostructures depicted highest photocatalytic activity exceeding 4.63 times greater than bare ZnO and 5.87 times higher than bare Ag2O. Interestingly, the prepared Ag2O-decorated ZnO heterostructures exhibited higher photocatalytic activity compared with commercially available photocatalysts such as Merck ZnO (27%), TiO2-P25 (22%) and TiO2-PC-50 (20%) under visible light irradiation. The high photocatalytic efficacy of Ag2O-decorated ZnO nanorods heterostructures could be ascribed to less electron hole recombination which led to high efficacy of synthesized nanocomposite under visible light. Different scavengers were also used to identify the role of reactive species in the photo-degradation process. (C) 2017 Elsevier B.V. All rights reserved.