Complete defluorination of PFASs via photocatalytic reduction in water.

Chong, MeiChi; Zhou, Qixin; Xu, Jingyi; Wu, Zhaohui; Zhu, Enwei; Li, Wenlu; Zhang, Ling; Guo, Yan et al. · Nat Commun · 2026

basic_science · Level V

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Abstract

The environmental persistence of per- and polyfluoroalkyl substances (PFASs), driven by the exceptional stability of their C-F bonds, presents a formidable challenge for remediation. Herein, we report the 5,10,15,20-tetraphenyl (4-aminophenyl) porphyrin (TAPP) aggregates as visible-light-driven photocatalysts capable of achieving almost-100% defluorination of PFASs without chemical additives. Central to this process is the ultra-stable TAPP radical species (TAPP<sup>•</sup>), which exhibits a lifetime exceeding 7 days under ambient conditions. Under visible-light irradiation, TAPP<sup>•</sup> generates reductive electrons with a potential of -2.68 V<sub>NHE</sub>, enabling injection into the C-F antibonding orbitals to initiate defluorination. The exceptional stability of TAPP<sup>•</sup> arises from intramolecular charge delocalization mediated by the synergistic overlap between the lone-pair electrons distribution of the amino groups and the highest occupied molecular orbital. This work develops a steady radical strategy that leverages charge-delocalization to engineer photocatalysts with highly reductive electron, offering an approach to address persistent environmental contaminants.