This study considered the green preparation, characterization, and investigation of the photocatalytic properties of zinc oxide magnetic nanostructure using electroplating industry effluent in the preparation. In this regard, the prepared structure was characterized by several common methods, including XRD, UV–Vis, FT-IR, DLS and VSM, and some of its properties were determined, including magnetic property, optical activity and surface charge. After determining the structure and confirming the optical activity of the prepared particles, its efficiency as a catalyst was evaluated in the photodegradation of methylene blue (MB) dye. Based on the results of the characterization of the structure of the ZnFe2O4 compound, the energy gap was calculated to be 3.46 eV. The results of DLS and VSM analyses showed that the prepared nanocomposite has average size, surface charge and magnetic properties equal to 65.5 nm, +95.94 mV and 8 emu/g, respectively. After confirming the photocatalytic properties of the prepared magnetic nanocomposite, the best operating conditions for the photocatalytic degradation of MB were determined to be 0.5 g of the photocatalyst, concentration of 10 mg/L of MB, pH equal to 9 and 1 mL of hydrogen peroxide (30 %) in 60 min (80 % degradation).
