Enhanced electrochemical degradation of aromatic organic pollutants through accelerated electron transfer using Fe-C structured rGO/Fe-NF

Abstract

The pervasive presence of aromatic organic pollutants, encompassing antibiotics and chemical raw materials, poses a significant and pressing threat to human health and safety. While the conventional electro-Fenton approach effectively addresses the challenges of superior efficacy, reduced energy consumption, and easy regulation through H2O2 supplementation, it remained confronted with challenges, including the formation of iron sludge and suboptimal electron utilization efficiency in H2O2 generation. Here, we adeptly synthesized a composite material comprising graphene and transition metal iron, which was then immobilized onto the nickel foam substrate to expedite electron transfer and catalyze the generation of hydroxyl radicals (·OH), thereby effectively degrading the target pollutants. The rGO/Fe2%-NF cathode system showed excellent removal effects on sulfadiazine, 2,2′,4,4′-tetrehydroxybenzophenone, and rhodamine B (100% within 120 min). In this process, dissolved oxygen molecules were converted into H2O2 through a two-electron pathway, and the main reaction species (·OH) was responsible for further activation. Furthermore, the formation of Fe-C bonds in rGO/Fe2%-NF cathode not only promotes direct electron transfer but also improves the structural and performance stability of the cathode. Notably, the toxicity assessment of intermediates displayed a marked decline, signifying the potential of the rGO/Fe2%-NF cathode system to ameliorate the imminent risks posed by micropollutants.