Co3O4 nanoparticles anchored on activated coke as an efficient peroxymonosulfate activator for bisphenol AF degradation: Performance and mechanism

Co 3 O 4 @AC composite was successfully synthesized for efficient PMS activation. • The AC support can effectively inhibit the self-aggregation of Co 3 O 4 nanoparticles. • 97.47% of bisphenol AF can be removed within 60 min in the Co 3 O 4 @AC/PMS system. • A dual radical/non-radical oxidation mechanism was confirmed, with 1 O 2 and SO 4 · - as the dominant active species. • The composite exhibited excellent cyclic stability with low cobalt leaching. Bisphenol AF (BPAF) is a typical refractory fluorinated organic pollutant with strong biological toxicity and poor biodegradation, posing potential hazards to aquatic ecosystems and human health. Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) have been widely recognized as efficient treatment technologies for organic wastewater, while the agglomeration of pure cobalt-based catalysts limits their practical activation and degradation performance. In this work, a Co 3 O 4 @AC catalyst was successfully constructed by a simple impregnation-calcination method using porous activated coke (AC) to load Co 3 O 4 nanoparticles. Structural characterization proved the successful loading of Co 3 O 4 on the AC carrier. The optimized Co 3 O 4 @AC composite achieved a satisfactory BPAF removal efficiency of 97.47% within 60 min. Electron paramagnetic resonance (EPR) tests and radical quenching experiments indicated that BPAF removal was primarily attributed to both radical and non-radical pathways, with SO 4 · - and 1 O 2 as the crucial active species. DFT calculations indicated that benzene rings and phenol hydroxyl groups were the primary reaction sites of BPAF. Two possible degradation pathways of BPAF were proposed, combined with the identified intermediate products. Furthermore, the composite exhibited excellent cyclic reusability and a low risk of cobalt ion leaching. This work provides a feasible strategy for treating fluorinated refractory wastewater and deepens the mechanistic understanding of carbon-supported metal oxide catalysts during PMS activation.