Investigations of the photoelectrochemical and photo-Fenton properties of TiO₂/FeOCl nanocomposites

The TiO₂/FeOCl composites were prepared by a simple calcination method, and the photo-Fenton performance of the TiO₂/FeOCl photo-Fenton catalysts was investigated for the degradation of Rhodamine B (RhB) and Tetracycline (TC) in simulated sunlight under different conditions. The structure, morphology, elemental composition and optical properties of the samples were investigated by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and ultraviolet–visible absorption spectroscopy (UV–vis). The results showed that the synthesized. TiO₂/FeOCl catalysts exhibited enhanced visible light absorption and excellent photo-Fenton performance. Compared with pure FeOCl, TiO₂/FeOCl has a stronger degradation ability for both RhB and TC, and within 10 min, the degradation rate of RhB reaches 90.9%, which is about 6 times the degradation efficiency of FeOCl, and the removal rate of TC reaches 86%, which is about 2 times the removal efficiency of FeOCl; within 60 min, the degradation rate of RhB reaches 98% and the degradation rate of TC reaches 94%. The heterojunction formed between TiO₂ and FeOCl inhibited the recombination of electron–hole pairs, and at the same time, the presence of e-promoted the cycling of Fe³⁺ and Fe²⁺ in FeOCl, which facilitated the generation of hydroxyl radicals (·OH) from H₂O₂ and improved the photo-Fenton activity to achieve the pollutant degradation effect. Free radical trapping experiments confirmed that hydroxyl radicals were the main active groups, and the possible mechanism of photo-Fenton degradation was analyzed in detail. In this study, the efficient photo-Fenton performance of TiO₂/FeOCl provides a new idea for the modification of pure FeOCl.