Constructing of Fe-Cu bimetallic MOFs derived electro-Fenton cathode for efficient norfloxacin removal

Abstract

Heterogeneous electro-Fenton (H-EF) is a promising technology for the removal of persistent organic pollutants. It is urgently necessary to exploit effective cathode. In this study, the development of a stable FeCu-N doped C is modified in carbon felt (FC12-NC@CF) as a cathode for norfloxacin removal in heterogeneous electro-Fenton. FC12-NC, with a typical rod-like morphology derived from Fe/Cu bimetal MOF, is synthesized via carbonization in N2. The synergistic effect of Fe-Cu accelerated electron transfers and remarkably enhanced the oxygen reduction reaction (ORR) toward the two-electron process (n = 2.13). At a wide pH range (pH 3–9), norfloxacin (NOR) is removed efficiently within 90 min, while the modified cathode has excellent stability and catalytic capacity after six recycle runs. A possible mechanism of NOR removal was suggested for this H-EF process, confirming that hydroxyl radicals were the main active species. Based on the experimental results, the intermediates of NOR and the possible degradation pathways were proposed. According to the Toxicity Estimation Software Tool (T.E.S.T.), the toxicity of NOR was predicted to be partly minimized after the H-EF reaction. The prepared cathode was cost-effective, demonstrating a good application prospect in wastewater treatment.