Mechanochemical Interface Engineering of FeS₂@CoS₂ Heterojunctions for Enhanced H₂O₂ Activation

With the acceleration of industrialization, the increasing presence of recalcitrant organic pollutants in wastewater has necessitated the development of highly efficient and stable catalytic systems. To address this challenge, this study adopted a heterostructure construction strategy involving hydrothermal synthesis combined with mechanical ball-milling optimization, successfully preparing a ball-milled-FeS₂@CoS₂ heterojunction catalyst (BM-FeS₂@CoS₂). The ball-milling treatment significantly improved the interfacial contact and electronic coupling between FeS₂ and CoS₂, thereby effectively enhancing the exposure and utilization efficiency of active sites. The material exhibited excellent performance in the degradation of Rhodamine B (RhB), achieving effective removal within a short time frame and maintaining high activity over multiple cycles across a wide pH range. Further mechanistic studies revealed that hydroxyl radicals (·OH) and singlet oxygen (¹O₂) were the primary active species. Benefiting from the advantages of the heterojunction structure, interfacial electron transfer not only promoted the generation of ·OH but also facilitated its partial conversion into ¹O₂, establishing a synergistic oxidation pathway involving both radical and non-radical species. This mechanism not only balances reaction rate and catalytic stability but also broadens the applicable pH range for heterogeneous Fenton-like reactions. In summary, ball-milling-driven interfacial optimization has been demonstrated as an effective strategy for constructing high-performance heterostructures, providing new insights for the design of efficient and stable heterogeneous Fenton-like catalysts.