Trace Adsorptive Removal of PFAS from Water by Optimizing the UiO-66 MOF Interface

The confluence of pervasiveness, bioaccumulation, and toxicity in freshwater contaminants presents an environmental threat second to none. Exemplifying this trifecta, per- and polyfluoroalkyl substances (PFAS) present an alarming hazard among the emerging contaminants. State-of-the-art PFAS adsorbents used in drinking water treatment, namely, activated carbons and ion-exchange resins, are handicapped by low adsorption capacity, competitive adsorption, and/or slow kinetics. To overcome these shortcomings, metal-organic frameworks (MOFs) with tailored pore size, surface, and pore chemistry are promising alternatives. Thanks to the compositional modularity of MOFs and polymer-MOF composites, herein we report on a series of water-stable zirconium carboxylate MOFs and their low-cost polymer-grafted composites as C₈-PFAS adsorbents with benchmark kinetics and "parts per billion" removal efficiencies. Bespoke insights into the structure-function relationships of PFAS adsorbents are obtained by leveraging interfacial design principles on solid sorbents, creating a synergy between the extrinsic particle surfaces and intrinsic molecular building blocks.