Insights into efficient activation of H2O2 by sulfur-doped CuFeO2: Important role of sulfur and sulfamethoxazole oxidation

In the field of advanced oxidation processes, the efficient activation of hydrogen peroxide (H2O2) plays a crucial role in the degradation of organic pollutants. Herein, sulfur-doped CuFeO2 (S-CuFeO2) was synthesized and exhibited enhanced catalytic activity for sulfamethoxazole (SMX) degradation via H2O2 activation. Sulfur incorporation into the CuFeO2 lattice modulates the electronic structure and surface properties, thereby facilitating H2O2 activation and promoting OO bond cleavage and the generation of highly reactive oxygen species (ROSs). Combined quenching experiments, electron spin resonance (ESR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations reveal that hydroxyl radicals (HO•) and superoxide radicals (O2•-) dominate the SMX degradation in oxidation process. In addition, the S-CuFeO2/H2O2 system demonstrates good stability, low metal leaching, and effective performance in different water matrices and for various organic pollutants. Toxicity evaluation further indicates a reduction in overall toxicity during degradation. This work provides mechanistic insight into H2O2 activation by sulfur-doped catalysts and offers a feasible strategy for designing efficient catalysts for antibiotic-contaminated wastewater treatment.