Fluorophilic N, S self-doped porous carbon electrodes derived from biomass gelatin for electro-Fenton degradation of GenX

Perfluorohexane-1,3-dicarboxylic acid (GenX) is now widely used as a substitute for the prohibited perfluorooctanoic acid (PFOA), which has caused growing concerns about its persistence and potential hazards to human health. This study developed a biomass gelatin-derived N and S self-doped porous carbon electrodes (NSGC), for the electro-Fenton (EF) degradation of GenX. To facilitate absorotion, diffusion, and degradation in EF, the NSGC was fluorinated to enhance the selectivit and binding energy between the catalyst and GenX by the “F-F interactions”. The resulted F-NSGC reach 58.8% electroadsorption efficiency to GenX in 60   min, and then degraded 95.8% with a mineralization rate of 63.2% within 180   min. The degradation mechanism was discussed by identifying intermediate products. Moreover, the F-NSGC can maintain a good degradation effect in complex ionic background conditions and actual water samples. These findings extend the applications of biomass-based carbon electrodes and consolidate the effect of F-F interactions on degradation of GenX and other per- and polyfluorinated alkyl substances.