Efficient Capture of Short‐ and Long‐Chain PFAS from Water by a Metal–Organic Framework

Per- and polyfluoroalkyl substances (PFAS), known as “forever chemicals,”present major environmental and health risks due to their extreme stabilityand dual hydrophobic–hydrophilic character, which complicates remediation.Conventional adsorbents such as activated carbon and ion-exchange resinsshow limited performance, particularly for short-chain PFAS. Metal–organicframeworks (MOFs) have emerged as promising alternatives owing to theirtunable porosity, large surface area, and adjustable functionality. Here, weassess the PFAS removal potential of a robust, water-stable, biologicallyderived MOF, CuII2 (S,S)-hismox·5H2 O (denoted 1), synthesized fromL-histidine. MOF 1 features medium-sized trapezoidal nanoscale channelsexhibiting both hydrophobic and hydrophilic character. It achieved highcapture efficiencies (80–100%) for long-chain PFAS (C7 –C 12 ), including PFDA,PFUnDA, PFDoDA, PFOS, and 8:2 FTSA, and remarkable removal rates of70% (PFBA) and 86% (PFBS) for short-chain analogues –surpassingconventional adsorbents and other reported MOFs. Excellent reusability andrapid adsorption kinetics were observed under continuous-flow solid-phaseextraction with contact times under 30 seconds. The high crystallinity of MOF1 also enabled single-crystal X-ray diffraction studies of encapsulated PFBAand PFOS (PFBA@1 and PFOS@1). These findings highlight MOF 1 as ahigh-performance, bio-derived platform for efficient PFAS remediation andadvance the development of MOF-based water treatment technologies