Boosting singlet oxygen generation through peroxymonosulfate activation over CeO₂-supported CuO catalyst to enhance...

Herein, a novel CeO₂-supported CuO composite (denoted as CuO/CeO₂) is rationally designed and synthesized via a facile strategy for peroxymonosulfate (PMS) activation to degrade fluorinated antibiotic (namely florfenicol). Benefiting from the synergistic effects between CeO₂ and CuO, abundant Ce³⁺/Ce⁴⁺ and Cu⁺/Cu²⁺ redox couples and oxygen vacancies are formed in the composite, which can significantly accelerate interfacial charge transfer and provide sufficient active sites. The optimized CuO/CeO₂ catalyst shows exceptional catalytic performance, achieving 95.9% removal efficiency of florfenicol within 16 min, together with excellent pH adaptability, anti-interference capacity, and reusability. The mechanistic analysis reveals that PMS is firstly adsorbed on the CuO/CeO₂ surface to form CuO/CeO₂-PMS* complexes, which then undergoes disproportionation to produce ¹O₂. Meanwhile, O₂^•- can also transform PMS into SO₅^•‒, which further decomposes into ¹O₂. The nonradical pathway dominated by ¹O₂ is responsible for the degradation of florfenicol, whereas radical species and high-valent copper contribute minimally. All in all, this work provides a high-efficiency strategy for selective ¹O₂ generation in advanced oxidation processes, offering a promising approach for fluorinated antibiotic wastewater remediation.