Z-scheme CuO/Fe3O4/GO heterojunction photocatalyst: Enhanced photocatalytic performance for elimination of tetracycline.

CuO/Fe3O4/GO, as a Z-scheme heterojunction catalyst, was successfully synthesized and used as a photocatalyst for removing tetracycline from aqueous solution. The CuO/Fe3O4/GO heterogeneous catalyst combines the narrow bandgap semiconductor CuO, oxygen vacancies of Fe3O4, and oxygen-containing reaction sites of GO. Without the addition of activators (persulfate or H2O2), the photocatalytic performance on decomposing tetracycline is very excellent. Compared with GO, Fe3O4, and CuO, CuO/Fe3O4/GO exhibits superior photocatalytic performance. Under visible light radiation, CuO/Fe3O4/GO generates h+ and ⋅O2-, which are the mainly responsible active groups for TC degradation. The effects of various pH, catalysts, and reuse on the degradation performance are evaluated, and the optimal conditions for CuO/Fe3O4/GO removal of tetracycline are obtained at pH 7, catalyst dosage 20 mg⋅L-1, TC at a concentration of 30 mg/L, nearly 97.3% of tetracycline is decomposed. This study has great potential in the treatment of wastewater containing various antibiotics.