Oxygen Vacancy-Enhanced Electrocatalytic Degradation of Tetracycline over a Co 3 O 4 –La 2 O 3 /Peroxymonosulfate System

Peroxymonosulfate (PMS) activated by metal oxides has been developed as a promising approach for advanced oxidation processes in the treatment of antibiotic containing wastewater; however, rapid and effective activation of PMS still lacks reasonable catalyst-oriented design. Here, by fabricating a Co 3 O 4 –La 2 O 3 bimetallic oxide electrode to implement defect engineering, we report an oxygen vacancy (OV)-mediated PMS activation electrocatalytic system for degradation of tetracycline (TC). The rare earth metal oxide La 2 O 3 was used to modify Co 3 O 4 and introduce OVs as active sites, where PMS is activated to produce reactive species. OVs in the Co 3 O 4 –La 2 O 3 composites facilitate the generation of singlet oxygen ( 1 O 2 ), which mediates the activation of PMS via a non-radical pathway. When the ratio of Co to La was 2:1, the system Co 3 O 4 –La 2 O 3 /PMS had a degradation efficiency for TC of more than 97.50% and a mineralization rate of up to 62.97% within 40 min. Overall, the findings on the defect-engineered materials for antibiotic degradation could provide an effective strategy for the treatment of antibiotic containing wastewater with low energy consumption and pollution.