The Polarized Electric Field on Fe-N-C-S Promotes Non-Radical Process of Peroxymonosulfate Degrade Diclofenac Sodium

Abstract The non-radical reaction based on persulfate is selective, so a large amount of inorganic anions and natural organic matter in the physical water environment can be ignored. In this work, Fe and S are doped into g-C3N4 for establishing a novel electronic bond bridge on Fe-N-C-S. The difference in electronegativity resulting in a local polarization electric field on Fe-N-C-S. Therefore, a closed electronic loop of pollutants/catalyst/oxidant is established, thereby promoting non-radical electron transfer. The kinetic reaction rate constant of pollutant degradation increased by 51 times (1.32719 min-1). Surface reactive complexes and 1O2 are the main mechanisms of diclofenac sodium degradation. Poisoning experiments and normalized fitting confirmed the key role of S and the active site of Fe-catalyzed PMS. The system shows good adaptability to inorganic anions, wide pH range (3-9) and natural water bodies. The study provides a way to improve the electron transfer process in non-radical reactions.