A CuO/ZnFe2O4 heterostructure as an efficient catalyst for NaBH4-assisted reduction of chloramphenicol.

In this study, a CuO/ZnFe2O4 heterostructure in the form of a flower, consisting of rod-like surface features associated with CuO on ZnFe2O4 microspheres, was successfully synthesized and evaluated for its catalytic reduction of chloramphenicol (CAP) in the presence of NaBH4. Structural and morphological analysis confirmed the successful formation of the heterostructure with enhanced contact between ZnFe2O4 and CuO. Compared to pure ZnFe2O4, the CuO/ZnFe2O4 catalyst exhibited significantly improved catalytic activity for CAP reduction. Reaction conditions strongly influenced reduction efficiency, with optimal performance at pH 6, a catalyst dosage of 2.5 g·L-1, and a short reaction time of 20 min. The enhanced catalytic performance under mild, environmentally friendly conditions highlights CuO's crucial role in promoting surface electron transfer and facilitating reduction. Kinetic analysis at room temperature indicated a change in apparent kinetic behavior during the reaction, with pseudo-first-order behavior in the initial stage and a tendency toward zeroth-order behavior at later times. This evolution is consistent with the involvement of surface-mediated catalytic processes. Overall, the CuO/ZnFe2O4 heterostructure shows significant potential as an efficient catalyst for rapid CAP reduction under near-neutral conditions, offering a promising strategy for wastewater treatment.