Controlling polymerization deposition route for phenols removal by interfacial defect engineering via Fenton-like...

Polymerization-deposition (PD) pathway offers a promising route for low-carbon wastewater treatment, yet their efficiency under ultra-low oxidant dosage remains challenging. Herein, interfacial asymmetric oxygen vacancies (As-Ov) were constructed in hollow Co₃O₄/CeO₂ composites (H-Co30Ce-Ov) using glucose-derived hydrothermal carbon microspheres as sacrificial templates. The interfacial As-Ov drives an electron-transfer pathway (ETP) for phenol (PN) removal via peroxymonosulfate (PMS) activation to generate phenoxy radicals. These radicals subsequently underwent coupling reactions to form oligomeric products, resulting in effective COD removal via a PD-dominated process under ultra-low PMS dosage. Mechanistic investigations, including in situ Raman and electrochemical analyses, confirms the critical role of the coordination environment of As-Ov in controlling PMS activation behavior and reaction kinetic. Moreover, the H-Co30Ce-Ov exhibited excellent catalytic activity toward electron-rich pollutants, high PMS utilization efficiency and good stability across different water matrices. This study provides a rational strategy to enhance PD-based catalytic oxidation and offers new insights into resource-oriented pollutant removal in wastewater treatment.