Peroxydisulfate Activation by Bimetallic CuMn Oxides Supported g-C3N5 with Nitrogen Vacancies for Antibiotic Degradation via Radical and Non-radical Pathways

The metal-nitrogen-carbon materials are considered as ideal candidates for activating peroxydisulfate (PDS) to remove organic pollutants in wastewater. However, the bimetallic oxides supported g-C 3 N 5 with nitrogen vacancies (Nvs) is little reported. In this work, a novel CuMn/g-C 3 N 5 -Nvs composite was fabricated by a simple method and then applied for the activation of PDS to degrade tetracycline (TC). A series of characterization results revealed that the the bimetallic CuMn oxides was successfully loaded onto the surface of g-C 3 N 5 , enriching catalytic active sites and forming more Nvs. The preparation of catalyst and related reaction conditions were systematically evaluated. The results showed that the degradation efficiency of TC by CuMn/g-C 3 N 5 -Nvs was 21 and 46 times higher than that of CuMnO x and g-C 3 N 5 . This enhancement was attributed to the synergistic effect among Cu and Mn ions, and Nvs in the CuMn/g-C 3 N 5 -Nvs. Furthermore, this catalyst exhibited a good stability. The quenching and electron spin resonance experiments confirmed that the TC removal was occurred through the co-existence of radical and non-radical pathways. Additionally, the biological toxicity tests demonstrated that its toxicity significantly decreased after treatment by the CuMn/g-C 3 N 5 -Nvs/PDS system. Overall, this work provided a feasible approach for constructing the composite containing Nvs and highlighted the potential treating process for environmental remediation.