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

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.