Fabrication of TiO2/CuFeO2 composites for oxytetracycline degradation through heterogeneous photo-Fenton-like process under visible light

Abstract

The heterogeneous photo-Fenton-like (HPF-like) catalyst TiO₂/CuFeO₂ was prepared by ball-milling and calcination for oxytetracycline (OTC) degradation. The systematic characterization indicated that the dispersion of TiO₂ nanoparticles onto CuFeO₂ improved visible light absorption and promoted electron transfer through heterojunction structure, benefitting photocatalytic activity. The optimum conditions were specified as 0.15 g/L TiO₂/CuFeO₂-0.3, 30 mM H₂O₂, and pH 9 through response surface methodology for HPF-like catalytic degradation efficiency (∼90 %) towards OTC. The TiO₂/CuFeO₂-0.3 showed superior reusability and stability, and also it had better degradation performance towards other tetracycline antibiotics. The quenching experiment and electron spin resonance analysis revealed two predominant active species (•O₂^- and •OH) in the HPF-like reaction. The increased separation and transfer of photogenerated carriers due to Z-scheme heterojunction and in-situ Fe³⁺/Fe²⁺ and Cu²⁺/Cu⁺ cycles were proposed to promote reactive oxygen species generation. The HPF-like system of TiO₂/CuFeO₂ composites may be an effective strategy for antibiotic degradation in water.