Ce-Doped In2S3 for Enhanced H2O2 Adsorption and Surface Hydroxyl Radical Engineering: Boosting Fenton-like Catalysis via Synergistic Redox Regulation

The photo-Fenton-like process is recognized due to its remarkable effectiveness in degrading recalcitrant organic pollutants, primarily due to its superior oxidative capabilities. In this work, we synthesized Ce-doped In 2 S 3 hollow-tube catalysts via a precursor-assisted method utilizing MIL-68(In). Within the photo-Fenton-like system, cerium acts as a Fenton-like cocatalyst, activating adsorbed H 2 O 2 through heterolytic cleavage and subsequently generating reactive oxygen species crucial for tetracycline (TC) degradation. Specifically, Ce selective adsorption of H 2 O 2 modulates the prevalent reactive species, shifting the dominant radical type from surface-bound ·OH to free ·OH radicals. Furthermore, the biological toxicity of TC degradation intermediates and their associated ecological risks were systematically evaluated. Radical speciation and reaction pathways were elucidated through a combination of density functional theory calculations and electron paramagnetic resonance analysis, culminating in a proposed catalytic mechanism. These results provide valuable insights into the rational design of photocatalysts aimed at antibiotic degradation and substantially expand the potential applications of rare-earth elements within advanced oxidation technologies.