Giuseppe Di Palma, Kasper Enemark-Rasmussen, Joerg R. Jinschek
Trifluoroacetic acid (TFA), an ultrashort-chain PFAS, is a ubiquitous molecule found in the environment, but conventional adsorption methods struggle to remove it because of its very low hydrophobicity. Here. we demonstrate that the zirconium-carboxylate metal-organic framework UiO-66, used in its as-synthesized wet gel form, captures TFA from aqueous solutions without further drying or thermal activation. Removal efficiencies (HEs) measured by 19F liquid-state NMR ranged from 30.1% to 70.5% and varied with adsorbent dosage (0.8-3.2 g wet gel per 40 mL). STEM-EDS elemental mapping of TFA-loaded gel revealed F co-localized with Zr throughout the aggregates. Deploying UiO-66 as a wet gel eliminates energy intensive activation and simplifies handling, highlighting a practical, low-energy route to mitigate ultrashort-chain PFAS in water. Further work will optimize regeneration media and validate performance in representative water matrices.