Electron-rich and electron-poor active centers induced by interface coupling to enhance the degradation of fluorinated antibiotic via peroxymonosulfate activation.

The water pollution issue triggered by antibiotic was a great challenge facing humanity, and it was necessary to develop an effective remediation technique. In this work, Fe₂O₃/Co₃O₄ composite with internal electric field was fabricated by a simple method. The presence of internal electric field reduced the interfacial resistance and facilitated the charge transfer, so stimulating the electron transport during reaction process. With the inducement of electrostatic force based on internal electric field, two active areas (namely electron-rich region and electron-deficient region) were formed at Fe₂O₃/Co₃O₄ composite. The electron-deficient active area (namely Co₃O₄ component) can oxidize peroxymonosulfate (PMS) to produce SO₅^•-, further turning into ¹O₂. In the meantime, the Fe₂O₃ component as electron-rich active area provided electrons to achieve the Fe-O-O heterolysis, then generating high-valent metal complexes. As predicted, the Fe₂O₃/Co₃O₄-driven PMS system displayed excellent ability to remove ofloxacin. Furthermore, the micro reactor loaded with Fe₂O₃/Co₃O₄ composite exhibited satisfactory performance in treating the wastewater containing ofloxacin. All in all, the effects of internal electric field on PMS activation are investigated in depth, which provided a valuable reference for future research.