Activation of peracetic acid by spinel FeCo2O4 nanoparticles for the degradation of sulfamethoxazole

Peracetic acid (PAA) can be activated to generate various radicals to degrade organic contaminants and holds great promise in wastewater treatment. Herein, a novel nano-sized magnetic spinel structured FeCo2O4 catalyst was synthesized by solgel method. It showed excellent performance in activating PAA for sulfamethoxazole (SMX) degradation. Acetyl(per)oxyl radicals (CH3C(O)O center dot and CH3C(O)OO center dot) were identified as the major reactive species attacking SMX. Surface chemistry characterization in combination with theoretical computation revealed that the catalytic activity of FeCo2O4 stems from the Co(II)/Co(III) cycling. PAA activation occurs on the FeCo2O4 (220) plane with higher adsorption energy (-5.10 eV) and d-band center (-1.56 eV). Although the Fe(III) in FeCo2O4 does not activate PAA directly, it increases the adsorption of PAA on the reaction plane and facilitates charge transfer, thus enhancing the activation. This work contributes to the understanding and rational designing of spinel-like Co-based materials for PAA-based water treatment.