Hydrated Electron‐Driven Defluorination Coupled With In Situ Mineralization: An Integrated Approach for SF ₆ 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 ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msubsup><mml:mi>e</mml:mi> <mml:mi>aq</mml:mi> <mml:mo>-</mml:mo></mml:msubsup> </mml:mrow> <mml:annotation>$e_{aq}^{-}$</mml:annotation></mml:semantics> </mml:math> ) 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.