A Hydrophobic Deep Eutectic Solvent Platform for Integrated PFAS Capture and <i>in Situ</i> Mild-Condition Mineralization

Per- and polyfluoroalkyl substances (PFAS) are highly persistent pollutants, and their remediation typically involves multistep processes, such as physical separation from contaminated water followed by chemical destruction, which are often costly, energy-intensive, and inefficient for short-chain PFAS. Here, we developed a dual-function system utilizing hydrophobic deep eutectic solvents (HDES) that enables efficient extraction of PFAS from water, concentrates them in the HDES phase, and facilitates their in situ degradation under mild conditions. Systematic experiments demonstrated that the HDES can achieve near-complete removal of a broad spectrum of PFAS, including short-chain and functionalized variants, through a combination of nonpolar and pH-dependent electrostatic interactions. The PFAS-enriched HDES phase supports their subsequent chemical destruction. Computational results revealed that the polar protic HDES facilitates the rate-determining step for PFAS destruction and experimental validation confirmed rapid PFAS degradation and deep mineralization typically over 87% across various PFAS structures within 24 h at 120 °C, with degradation initiated at temperatures as low as 90 °C. Integration studies confirmed sustained extraction over multiple cycles and effective sequential degradation. This HDES-based system offers a transformative approach to PFAS remediation, combining scalability, versatility, and sustainability for the efficient treatment of PFAS-contaminated water.