Three-dimensional (3D) CuO/TiO 2 hybrid heterostructure nanorod arrays (NRs) with noble-metal-free composition, fabricated by template-assisted low-cost processes, were used as the photo-Fenton-like catalyst for dye degradation. Here, CuO NRs were deposited into anodic aluminum oxide templates by electrodeposition method annealed at various temperatures, followed by deposition of TiO 2 thin films through E-gun evaporation, resulting in the formation of CuO/TiO 2 p-n heterojunction. The distribution of elements and compositions of the CuO/TiO 2 p-n heterojunction were analyzed by EDS mapping and EELS profiles, respectively. In the presence of H 2 O 2 , CuO/TiO 2 hybrid structure performed more efficiently than CuO NRs for Rhodamine B degradation under the irradiation of 500-W mercury-xenon arc lamp. This study demonstrated the effect of length of CuO NRs, on the photo-degradation performance of CuO NRs as well as CuO/TiO 2 heterostructure. The optimized CuO/TiO 2 hybrid NR array structure exhibited the highest photo-degradation activity, and the mechanism and role of photo-Fenton acting as the catalyst in photo-degradation of dye was also investigated.