The synergistic effect of oxygen vacancies and acidic properties of SO42−/CexZr1−xO2 on enhancing the Electro-Fenton performance in antibiotics wastewater treatment

Recently, bi-functional catalysts have emerged as an effective approach for enhancing the performance of electro-Fenton in degrading antibiotics by simultaneously improving H 2 O 2 generation and Fe circulation. Herein, we prepared a SO 4 2- modified Ce x Zr 1-x O 2 bi-functional catalyst to construct an efficient e-Fenton system for degrading norfloxacin. Results display that the fabricated catalyst exhibited superior performance in degrading norfloxacin owing to durative generated ⋅OH, which was proved to be the dominant active species. The H 2 O 2 generation capacity of that catalyst was twice higher than the pure e-Fenton and its faradaic efficiency even came up to 75%. The amount of soluble total Fe and Fe 2+ ions of that catalyst were both increased twofold compared to the blank system, declaring the acceleration of Fe recycling process. Characterizations and density function theory calculations proposed a synergistic mechanism that attributed the simultaneously improvement in H 2 O 2 generation and Fe 2+ circulation to the multiple regulated interface properties, the promoted 2e - ORR activity caused by enriched oxygen vacancies at Ce sites, and the accelerated electrons transfer owing to the strengthened acidic sites for the coordination between Zr sites and S species. Furthermore, that catalyst is also proved to be feasible, well-recycled and practical for application in wastewater purification.