Reactive soft-template engineering of porous oxygen-vacancy-rich copper ferrite for peroxymonosulfate activation toward tetracycline degradation

Designing low-cost heterogeneous catalysts that simultaneously offer accessible pore channels, abundant surface defects, and efficient interfacial electron transfer is important for peroxymonosulfate (PMS)-based antibiotic oxidation. In this work, porous copper ferrite-based catalysts were synthesized through a solvent-free grinding-calcination strategy using glucose, citric acid, and oxalic acid as reactive soft templates. The oxalic-acid-derived catalyst (O-CFO) showed a CuFe 2 O 4 /Fe 2 O 3 composite structure with a macroporous architecture and the highest oxygen-vacancy content, achieving a tetracycline (TC) removal efficiency of 92.4% within 60 min and an apparent rate constant of 0.073 min −1 , outperforming glucose- and citric acid-derived samples. The O-CFO/PMS system maintained efficient TC degradation over a broad pH range of 3.2–9.1 and was tolerant of common coexisting constituents and real water matrices. Quenching and electrochemical results suggest that 1 O 2 , •OH, SO 4 •- , and surface-mediated electron-transfer pathways jointly contribute to TC oxidation. This study demonstrates a scalable soft-template route for constructing porous oxygen-defective CuFe-based catalysts for PMS-driven antibiotic abatement.