Electro-assisted heterogeneous peroxymonosulfate activation on NiFe2O4 coated nickel foam cathode for tetracycline degradation: Synergistic efficacy and mechanism

Abstract

BackgroundThe electro-assisted inverse spinel catalytic peroxymonosulfate (PMS) activation system is a highly promising technology for the degradation of the antibiotic by in-situ and stably produced reactive species. MethodsHerein, a reverse-structured spinel ferrite NiFe2O4 grown on nickel foam (NF) serves as the cathode, and a platinum sheet serves as the anode, constructing a novel ECNiFe2O4/NF-PMS system. Significant FindingsUnder optimal conditions, the system achieves a remarkable 81.7 % degradation of 30 mg/L tetracycline (TC) within 60 min, surpassing other oxidation systems. Comparative radical scavenger experiments under air and N2 conditions reveal that radicals generated from PMS activation, in-situ generated H2O2, and electrode reactions collectively contribute to TC degradation, with 1O2 playing a pivotal role. The introduction of electrochemical reactions promotes ion diffusion, electron transfer and redox cycles of metal active sites, synergistically improving the activity and stability of the heterogeneous PMS activation system. The ECNiFe2O4/NF-PMS system selectively attacks the side aromatic rings of TC, leading to a reduction in the overall ecological toxicity of intermediate products, as confirmed by the Toxicity Estimation Software Tool. Moreover, the system exhibits robust resistance to the interference of coexisting substances, indicating its promising practical application potential for antibiotic degradation.