Currently, nanoparticles are regarded as excellent materials for degrading and removing dyes due to their beneficial surface features and chemical reactivity. Herein, Cu doped ZnO (CZ) was co-doped with Fe (FCZ) at different concentrations (2, 3, 4 and 8 wt% with respect to CZ) via simple one-step co-precipitation approach. The structural, surface morphology, surface properties, optical and photocatalytic performance of prepared samples were studied. Due to the doping of Fe, the band gap of CZ reduced from 2.7 eV to 2.29 eV, which is beneficial for absorbing visible light. Among doped CZs, 4 wt% Fe-doped CZ (4FCZ) exhibited 97.1% methylene blue (MB) degradation at neutral pH under 60 min of sunlight exposure. Furthermore, the effect of initial concentration of dye, catalyst load, and pH on the degradation process was investigated. The remarkable photocatalytic activity of 4FCZ nanoparticles can be attributed to their advantageous surface properties, such as their high specific surface area, heterostructure morphology, and mesoporous nature. Scavenger study identified •O2−, e−, and h+ as main reactive species. Pseudo-first order kinetics revealed degradation order: 4FCZ>8FCZ>3FCZ>2FCZ>CZ. 4FCZ showed recyclability with 90.9% MB degradation after three cycles. Mineralization of MB was analysed by COD and LC-MS studies. Fe-doped CZ emerges as a promising, cost-effective wastewater treatment under sunlight without special equipment. This study provides new insights on synthesis of ternary nanocatalyst for dye degradation.