Enhanced sulfamethoxazole (SMX) degradation via interfacial peroxymonosulfate activation by CuFe2O4 under microwave irradiation

To overcome mass-transfer limitations in solid–liquid catalytic reactions, a microwave-assisted system was developed based on bimetallic CuFe 2 O 4 spinel for peroxymonosulfate (PMS) activation. The catalyst achieved efficient sulfamethoxazole (SMX) degradation with a remarkable rate constant of 0.36 min −1 , representing an approximately 72 times faster rate than the non-microwave CuFe 2 O 4 /PMS system and superior to most reported analogues. Additionally, the microwave-assisted CuFe 2 O 4 /PMS system demonstrated higher efficiency than the PMS-only, Fe 3 O 4 /PMS, and CoFe 2 O 4 /PMS systems, which confirms the crucial role of Cu in the spinel structure. Quenching tests confirmed that superoxide radicals ( • O 2 − ) generated at the catalyst-solution interface played a dominant role. The system exhibited excellent stability and strong anti-interference ability across a wide pH range (3.0–9.0) and against common inorganic anions (Cl − , SO 4 2− , and HCO 3 − ). Under optimized conditions (1 g ·L −1 catalyst dosage and 700 W microwave power), nearly complete SMX removal was achieved within 20 min. XRD and XPS characterization confirmed that the crystal phase and chemical state of the CuFe 2 O 4 catalyst remained stable before and after the reaction. This study presents an efficient, stable approach for removing antibiotics from water and underscores the potential of microwave-enhanced interface catalysis in advanced oxidation processes.