Micelle-Mediated Hydrated Electron Capture Enables Efficient C–F Bond Activation and PFAS Mineralization

Abstract

Per- and polyfluoroalkyl substances (PFAS) present a major challenge in environmental remediation due to their extreme persistence and resistance to conventional chemical treatments. While recent advances in reductive approaches using hydrated electrons ( e aq – ) have shown promise for C–F bond activation, most require high photosensitizer loadings, suffer from poor electron utilization, and lack compatibility with diverse PFAS structures. Here, we report a micellar photocatalytic system using the cationic surfactant cetyltrimethylammonium bromide (CTAB) under UV irradiation to enhance e aq – utilization for PFAS degradation. A diverse range of legacy and emerging PFAS compounds containing sulfonate (–SO 3 – ), carboxylate (–CO 2 – ), hydrocarbon (–C 2 H 2 –), and ether (–O–) moieties, were completely degraded with fewer than four C–F bonds remaining in transformation products. Characterization revealed strong interactions between CTAB and PFAS, which spontaneously formed positively charged cationic–anionic micelles even at low concentrations. These micelles act as nanoreactors, trapping e aq – from the bulk phase, suppressing geminate recombination, and facilitating direct electron transfer to PFAS molecules. A comprehensive degradation pathway was identified, involving micellization, electron trapping, PFAS activation, and downstream radical-mediated reactions that lead to further destruction. The UV/CTAB system demonstrated sustained performance across multiple treatment cycles and exhibited resilience to oxygen and common aqueous cocontaminants. These findings reveal that efficient utilization of e aq –, rather than their abundance, governs C–F bond activation and PFAS degradation. This approach enables integrated PFAS separation and mineralization while establishing a framework for designing scalable, photosensitizer-free redox systems.

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