Pore structure modulation and surface functionalization boosted adsorption of PFAS on porous carbon: Experimental and...

Pore structure modulation and surface functionalization of porous carbon is essential for enhancing the adsorption efficiency of per- and polyfluoroalkyl substances (PFAS) and understanding their adsorption mechanisms. In this study, a novel porous carbon material was synthesized through integrated hydrothermal carbonization and pyrolysis. Fine modification was achieved by optimizing ZnCl₂ impregnation ratios (4:1), pyrolysis temperatures (500 °C), and acid washing, yielding fine-tuned microporosity, disordered graphitic domains, and diverse oxygen groups. The resulting porous carbon exhibited a highly developed microporous structure, disordered graphitic regions and diverse oxygen-containing functional groups. Adsorption experiments demonstrated excellent removal capacity for both long-chain and short-chain PFAS under varying pH and concentrations. Notably, Glu-Zn4-500 achieved a maximum adsorption capacity of 476 mg/g for PFOA and showed superior dynamic regenerability over commercial activated carbon. At environmentally relevant PFAS concentrations ( 500 ng/L), rapid adsorption was observed within one minute, even in the presence of natural organic matter (NOM) and Ca^2 + . Theoretical calculations demonstrate that PFAS adsorption arises from synergistic contributions of hydrophobic anchoring of perfluoroalkyl chains on graphitized domains and polar interactions (electrostatic/hydrogen bonding) at functional groups. This work highlights a design strategy for high-performance PFAS adsorbents applicable to complex water matrices.