Highly effective C-O-Fe and C-O-Co dual electronic channels in Co/Fe-carbon fiber aerogels for boosted peroxymonosulfate activation

Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) offer a promising method for organic pollutant degradation, but the activation efficiency of PMS is limited by slow electron transfer between the catalyst and PMS. To address this issue, a novel Fenton-like catalyst, Co/Fe-carbon fiber aerogels (PCF), was synthesized using dynamic hot impregnation and calcination. The Co/Fe-PCF catalyst forms dual reaction centers (DRCs) with electron Co or Fe-rich sites and electron C-deficiency site connected by single-electron bond bridges, referred to as Bi-DRCs (BDRCs). These BDRCs enhance electron transfer, boosting redox reactions and surface-active site utilization. Electrochemical analysis shows that the proposed Co/Fe-PCF exhibits a higher current density and lower charge transfer resistance compared to PCF, making it more favorable for electron transfer. The Co/Fe-PCF-PMS system achieved 99.91 % ornidazole degradation within 5 min, with a rate constant of 1.16 min⁻¹. The catalyst also efficiently degraded a wide range of recalcitrant pollutants. Mass spectrometry analysis identified the degradation intermediates of ornidazole, and their toxicity was assessed. ONZ and its degradation intermediates undergo complete degradation in the Co/Fe-PCF/PMS system, leading to a significant reduction in toxicity. This study advances BDRCs catalysts for PMS-AOPs in pollutant degradation.