A CuO/ZnFe 2 O 4 heterostructure as an efficient catalyst for NaBH 4 -assisted reduction of chloramphenicol

In this study, CuO/ZnFe 2 O 4 heterostructure in the form of flower, consisting of CuO nanorods anchored on ZnFe 2 O 4 microspheres, was successfully synthesized and evaluated for its catalytic reduction of chloramphenicol (CAP) in the presence of NaBH 4 . Structural and morphological analysis confirmed the successful formation of the heterostructure with enhanced contact between ZnFe 2 O 4 and CuO. Compared to pure ZnFe 2 O 4 , the CuO/ZnFe 2 O 4 catalyst exhibited significantly improved catalytic activity for CAP reduction. The reduction efficiency was strongly influenced by reaction conditions, with optimal performance achieved at pH 6, a catalyst dosage of 2.5 g/L, and a short reaction time of 20 minutes. The enhanced catalytic performance under mild, environmentally friendly conditions highlights the crucial role of CuO in promoting surface electron transfer and facilitating reduction. Kinetic analysis at room temperature revealed a shift from pseudo-first-order to zero-order kinetics throughout the reaction, suggesting surface-mediated catalysis. This evolution indicates that decatalysis is primarily governed by a surface-mediated Langmuir–Hinshelwood mechanism. Overall, the CuO/ZnFe 2 O 4 heterostructure shows significant potential as an efficient catalyst for rapid CAP reduction under neutral conditions, offering a promising strategy for wastewater treatment.