Coupling nitrogen/oxygen self-doped biomass porous carbon cathode catalyst with CuFeO2/biochar particle catalyst for the heterogeneous visible-light driven photo-electro-Fenton degradation of tetracycline

Abstract

The heterogeneous visible-light driven photo-electro-Fenton (H-VL-PEF) system was built to degrade tetracycline using nitrogen/oxygen biomass self-doped porous carbon (NO/PC) cathode catalyst coupling CuFeO2/biochar particle catalyst. The NO/PC possessed the H2O2 selectivity of 85.3%, and the gas diffusion electrode with NO/PC as cathode catalyst (NO/PC-GDE) exhibited fine H2O2 electrogeneration performance and stability. The generated electrons on CuFeO2/biochar by electrostatic induction and light excitation promoted Fe3+/Fe2+ and Cu2+/Cu+ redox cycle, which was beneficial for HO•/O2•- formation and tetracycline degradation. The introduction of CuFeO2/biochar catalyst and visible light could reduce energy consumption and promote tetracycline mineralization. The CuFeO2/biochar loads, initial pH and current density of H-VL-PEF system were optimized. The degradation pathway of tetracycline was speculated based on the intermediates identified by HPLC/MS. Escherichia coli growth inhibition experiments and toxicity prediction analysis demonstrated that the comprehensive toxicity of tetracycline was alleviated due to the catalytic degradation of H-VL-PEF system.