WS₂-modified schwertmannite for highly efficient dye wastewater degradation via enhanced Fe cycle in heterogeneous...

The primary challenge of heterogeneous Fenton lies in the inefficient ferrous cycle, which prevents it from effectively activating hydrogen peroxide (H₂O₂) to generate more reactive radicals (e.g., •O₂^-, •OH). The creation of a novel iron-based solid material, functionalized with various chemical groups, is critical for optimizing radical generation. In this study, WS₂ introduction during the mineralization process of schwertmannite (Sch) reduced particle agglomeration and enhanced methylene blue (MB) removal efficiency across a broad pH range (2-9) using WS₂-modified schwertmannite (WS₂@Sch) catalyst. Over 90 % of MB (initial pH 6, H₂O₂ 8.8 mmol/L, and WS₂@Sch 1 g/L) was efficiently removed within 3 min by WS₂@Sch-driven heterogeneous Fenton reaction. This effective elimination was attributed to abundant reactive species, primarily •OH, and ¹O₂. The superior catalytic performance of WS₂@Sch originated from enhanced Fe³⁺ and Fe²⁺ cycling, facilitated by the electron donation from the W⁴⁺/W⁶⁺ redox couple. This work demonstrates an efficient MB removal technology while providing critical insights for designing high-performance heterogeneous Fenton catalysts for dye wastewater treatment.