Halogen atoms doped FeOCl promoting Fe (II)/Fe (III) cycles to accelerate the photo-Fenton-like progress

Abstract

FeOCl possesses a layered structure that not only effectively catalyzes the degradation of organic pollutants under visible light but has also garnered significant attention for its Fenton-like reaction properties in pollutant degradation. In this study, pure FeOCl and halogen-doped X–FeOCl (X = Br, F, I) were synthesized, exhibiting bandgap widths of 1.77 eV for pure FeOCl and 1.67, 1.69, 1.72 eV for the doped versions, respectively. The X–FeOCl catalysts demonstrated superior photocatalytic activity and Fenton-like properties in the degradation of methylene blue across various pH conditions under simulated visible light exposure. Notably, under neutral conditions, F–FeOCl showed a degradation constant (k) that was 14.56 times higher than that of pure FeOCl during the photo-Fenton-like catalytic process within 30 min. Furthermore, Density Functional Theory (DFT) calculations revealed that structural distortion and reduced symmetry in X–FeOCl play critical roles in boosting electronic interactions at the doped sites, thereby facilitating the photo-Fenton-like reaction. This task enhances the understanding of FeOCl-based materials as photo-Fenton-like catalysts and offers insights into their applications in water purification and broader environmental remediation based on the degradation of MB dye.