Visible light-peroxomonosulfate coactivation via CuOx/Fe2O3 composites for efficient degradation of tetracycline and bimetallic mechanisms

A novel CuO x /Fe 2 O 3 composite catalyst was synthesized by a hydrothermal method and systematically evaluated for its peroxomonosulfate (PMS) activation capability under visible light irradiation, using tetracycline hydrochloride (TC-HCl) as the model pollutant. The results demonstrated that the CuO x /Fe 2 O 3 catalyst exhibited excellent catalytic oxidation performance, achieving 92.1 % TC-HCl degradation within 30 min through the generation of multiple reactive oxygen species (ROS) under visible light, including superoxide radicals (•O 2 − ), sulfate radicals (•SO 4 − ), hydroxyl radicals (•OH) and singlet oxygen ( 1 O 2 ). The mechanistic studies revealed that synergistic interaction between Fe and Cu bimetallic components significantly enhanced PMS activation efficiency, generating more reactive species and thereby increasing the degradation rate of TC-HCl. In addition, the CuO x /Fe 2 O 3 /PMS/vis system effectively degraded different pollutants (including Ciprofloxacin, Phenol, and Rhodamine B) and showed good tolerance to humic acid (HA) and salinity, among others. These findings highlight the practical potential of the CuO x /Fe 2 O 3 /PMS/vis oxidation system for the removal of organic pollutants in wastewater treatment field.