Oxygen Vacancy-Enhanced Electrocatalytic Degradation of Tetracycline over a Co3O4–La2O3/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 Co3O4–La2O3 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 La2O3 was used to modify Co3O4 and introduce OVs as active sites, where PMS is activated to produce reactive species. OVs in the Co3O4–La2O3 composites facilitate the generation of singlet oxygen (1O2), which mediates the activation of PMS via a non-radical pathway. When the ratio of Co to La was 2:1, the system Co3O4–La2O3/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.