Hydrated Electron-Driven Defluorination Coupled With In Situ Mineralization: An Integrated Approach for SF6 Degradation and Fluoride Immobilization.

The extreme atmospheric persistence of sulfur hexafluoride (SF6), coupled with its high global warming potential, necessitates effective degradation strategies. Herein, we report a reduction-precipitation platform that simultaneously achieves SF6 defluorination and in situ fluoride immobilization. Hydrated electrons ( e aq - $e_{aq}^{-}$ ) generated via photoreduction drive the cleavage of SF bonds, achieving enhanced SF6 degradation. Crucially, in situ precipitation with calcium salts directly converts the released fluoride ions into fluorite (CaF2), eliminating secondary pollution. XRD analysis confirmed complete phase transformation to pure CaF2 within 24 h using either Ca(OH)2 or CaCl2 as the calcium source, with fluoride mineralization efficiency exceeding 98%. This integrated approach of reduction and mineralization offers a new solution for managing SF6 and may offer insights for the degradation of other fluorinated greenhouse gases.