2D graphite carbon confined Fe₃O₄ anode triggering non-radical activation of peroxymonosulfate for carbamazepine...

This study developed a two-dimensional graphite carbon confined Fe₃O₄ catalyst using coal tar pitch as the carbon source. The constructed E-Fe₃O₄@C-PMS system (integrating confined Fe₃O₄ with electro-activated PMS) achieved 97.4 % removal of carbamazepine (CBZ) with a rate constant of 0.082 min^-1, which was 1.5 times higher than that of the non-confined E-Fe₃O₄-PMS system (0.054 min^-1). Electrochemical testing indicated that the incorporation of 2D graphite carbon markedly improved the electrical conductivity and electrochemically active surface area (ECSA) of Fe₃O₄@C. Quenching experiments and EPR analysis revealed that graphite carbon confinement regulated the PMS activation pathway towards a predominantly non-radical mechanism. XPS analysis confirmed that the confinement effect promoted redox cycling of Fe^III/Fe^II, sustaining the high catalytic activity of Fe₃O₄@C against PMS. DFT calculations suggested that the graphite carbon layer reconstructed the Fe 3d energy band distribution through interfacial charge transfer and orbital hybridization, rendering it favorable for the generation of ¹O₂. Degradation experiments in aquatic environments demonstrated that the Fe₃O₄@C-PMS system exhibited strong resistance to ionic interference. Furthermore, the 2D confinement effectively reduced Fe ion leaching, enabling long-term stability of Fe₃O₄@C. Overall, this study offered a novel strategy for designing efficient and robust electro-activated PMS system with substantial potential for the treatment of recalcitrant pollutants.