Fe-doped CeO2 catalyst for visible light-driven peroxymonosulfate activation: synergistic radical and non-radical pathways in tetracycline degradation

Widespread antibiotic contamination in aquatic environments has become a serious global concern, demanding efficient and sustainable treatment technologies. Fe-doped CeO 2 were synthesized via a simple impregnation method to efficiently activate peroxymonosulfate (PMS) under visible light irradiation for the degradation of TC. The introduction of Fe into the CeO 2 lattice effectively regulated the electronic structure and increased oxygen vacancy density, thereby enhancing charge separation and accelerating electron transfer to PMS for reactive oxygen species (ROS) generation. Under optimal conditions (0.4 mM PMS and 40 mg L −1 catalyst), the Light/2%Fe–CeO 2 /PMS system achieved a 98.2% TC removal within 45 min of LED irradiation, demonstrating superior oxidant utilization and stability across various water quality conditions and multiple tc antibiotics. Mechanistic investigations confirmed the coexistence of radical (·O 2 − , ·SO 4 − , ·OH) and non-radical ( 1 O 2 and direct electron transfer) pathways with strong synergistic effects. Density functional theory (DFT) calculations further revealed that Fe doping facilitates PMS activation and pollutant adsorption by promoting interfacial charge transfer and modulating the Ce 3+ /Ce 4+ redox cycle. This work provides new insights into the rational design of Fe-doped visible light-responsive catalysts for PMS-based advanced oxidation processes, offering a cost-effective and environmentally friendly strategy for antibiotic removal and sustainable wastewater treatment.