Performance and mechanism of FeS2/FeSxOy as highly effective Fenton-like catalyst for phenol degradation.

Developing a highly efficient Fenton-like catalyst working in a wide pH range is imperative to accomplish its practical wastewater treatment. Herein, FeS₂/FeS_xO_y catalyst was synthesized by hydrothermal-solvothermal vulcanization with thioacetamide as a sulfur source. Characterization results confirmed FeS₂/FeS_xO_y consisted of pyrite, kornelite, and szomolnokite. FeS₂/FeS_xO_y exhibited superior catalytic activity toward H₂O₂ activation with more than 96% phenol removal within 5 min in pH 3.0 ∼ 8.0 at 30°C. Radical scavenging experiment and EPR analysis revealed both hydroxyl radicals (·OH) and superoxide anion radicals (O₂·^-) anticipated in phenol elimination, but ·OH played a dominant role. The detailed degradation experiments and density functional theory (DFT) calculation confirmed the vital role of FeS₂ in enhancing phenol abatement. This study not only developed a highly active catalyst for H₂O₂ activation but also theoretically analyzed the FeS₂ function in depth, which provided a guide for designing a highly efficient Fenton-like catalyst. [ABSTRACT FROM AUTHOR]