Oxygen Vacancy-Enhanced Electrocatalytic Degradation\nof Tetracycline over a Co₃O₄–La₂O₃/Peroxymonosulfate System

Abstract

Peroxymonosulfate\n(PMS) activated by metal oxides has been developed\nas a promising approach for advanced oxidation processes in the treatment\nof antibiotic containing wastewater; however, rapid and effective\nactivation of PMS still lacks reasonable catalyst-oriented design.\nHere, by fabricating a Co₃O₄–La₂O₃ bimetallic oxide electrode to implement defect engineering,\nwe report an oxygen vacancy (OV)-mediated PMS activation electrocatalytic\nsystem for degradation of tetracycline (TC). The rare earth metal\noxide La₂O₃ was used to modify Co₃O₄ and introduce OVs as active sites, where PMS is activated\nto produce reactive species. OVs in the Co₃O₄–La₂O₃ composites facilitate the generation\nof singlet oxygen (¹O₂), which mediates the\nactivation of PMS via a non-radical pathway. When the ratio of Co\nto La was 2:1, the system Co₃O₄–La₂O₃/PMS had a degradation efficiency for TC of more\nthan 97.50% and a mineralization rate of up to 62.97% within 40 min.\nOverall, the findings on the defect-engineered materials for antibiotic\ndegradation could provide an effective strategy for the treatment\nof antibiotic containing wastewater with low energy consumption and\npollution.