2026-10-11T18:46:19Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34025311 2026-09-29T17:09:53Z category_1 category_4 category_915 category_7 category_8 category_12 category_272 category_873 category_64 category_135 portal_63 item_type_6 month_year_09_2026

Sustained Fe³⁺/Fe²⁺ Cycling Enables Photochemical Defluorination of Perfluoroalkyl Carboxylic Acids via Ligand-to-Metal Charge Transfer Jialei Guo (8658579) Peng Zhang (2071) Jinfeng Lu (2120329) Feng He (47348) Bo Fang (169627) Hao Yu (157186) Hongwen Sun (1421434) Biophysics Biochemistry Physical Sciences not elsewhere classified Medicine Microbiology Cell Biology Environmental Sciences not elsewhere classified Chemical Sciences not elsewhere classified Cancer Computational Biology within 420 min within 240 min widespread persistent pollutants perfluoroalkyl carboxylic acids oxidizing intermediates rather metal charge transfer generating perfluoroalkyl radicals fundamental chemistry governing experimental evidence revealed achieved complete defluorination 405 nm irradiation chain trifluoroacetic acid chain perfluorooctanoic acid lmct initiated decarboxylation energy uv irradiation driven photodefluorination strategy using commercial fe 3 +</ sup 2 +</ sup oxidative chain chain length threaten environmental subsequently degraded shortening reactions redox cycle polyfluoroalkyl substances nonaqueous media molecular oxygen mechanistic framework inversely correlated human health findings establish degradation rates broadly applicable Per- and polyfluoroalkyl substances (PFASs) are widespread persistent pollutants that threaten environmental and human health. Although Fe³⁺-mediated ligand-to-metal charge transfer (LMCT) has been shown to promote PFAS photochemical defluorination, existing systems rely predominantly on high-energy UV irradiation, often achieve incomplete defluorination, and generally exhibit poor performance toward short-chain and ultrashort-chain PFASs. Herein, we report a near-UV- to visible-light-driven photodefluorination strategy for perfluoroalkyl carboxylic acids (PFCAs) using commercial Fe³⁺ salts in acetonitrile under 405 nm irradiation, which achieved complete defluorination of long-chain perfluorooctanoic acid (PFOA) within 420 min and ultrashort-chain trifluoroacetic acid (TFA) within 240 min. Mechanistic studies combining density functional theory calculations and experimental evidence revealed that LMCT initiated decarboxylation, generating perfluoroalkyl radicals that subsequently degraded through oxidative chain-shortening reactions. The Fe³⁺/Fe²⁺ redox cycle was sustained by molecular oxygen, with hydroxyl and superoxide radicals playing auxiliary roles in reoxidizing Fe²⁺ and oxidizing intermediates rather than directly attacking intact PFOA. This strategy is broadly applicable to C2–C9 PFCAs, where the degradation rates are inversely correlated with chain length and are effective against perfluoroalkyl ether carboxylic acids. These findings establish a mechanistic framework for Fe³⁺-mediated PFAS photodefluorination in nonaqueous media and clarify the fundamental chemistry governing this process. 2026-09-29T00:00:00Z Text Journal contribution 10.1021/acs.est.6c11840.s001 https://figshare.com/articles/journal_contribution/Sustained_Fe_sup_3_sup_Fe_sup_2_sup_Cycling_Enables_Photochemical_Defluorination_of_Perfluoroalkyl_Carboxylic_Acids_via_Ligand-to-Metal_Charge_Transfer/34025311 CC BY-NC 4.0