Emerging materials for per- and polyfluoroalkyl substances (PFAS) removal from water

Per- and polyfluoroalkyl substances (PFASs) have appeared as a critical class of lasting ecological contaminants because of their extreme chemical stability, bioaccumulation capacity, and negative health impacts. Traditional treatment approaches, like activated carbon adsorption and ion exchange, in addition to membrane filtration, often demonstrate restricted effectiveness, particularly for short-chain PFASs and under complex water matrices. Consequently, the development of advanced, in addition to emerging, materials has become a central focus for effective PFAS remediation from contaminated water systems. Recent research highlights the promise of several innovative material classes, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs), layered double hydroxides (LDHs), cyclodextrin-based materials and ionic liquids (ILs), in addition to deep eutectic solvents (DESs). These materials exhibit tunable surface chemistry, high porosity, and tailored functional groups that facilitate multiple adsorption mechanisms like electrostatic attraction, hydrophobic and fluorophilic interactions, and hydrogen bonding. Furthermore, hybrid and composite systems offer enhanced selectivity, reusability, and operational efficiency. The incorporation of fluorinated moieties and functional groups capable of specific PFAS recognition further improves sorption capacity and selectivity. In addition, the advent of green and sustainable extraction media, such as biocompatible DESs and recyclable IL-based systems, represents a step toward environmentally responsible remediation technologies. Notwithstanding these developments, obstacles remain in achieving scalable deployment of these materials, maintaining performance in complex environmental conditions, and ensuring cost-effective regeneration. Emerging materials represent a transformative avenue for the specific and efficient elimination of PFASs from aqueous environments, bridging the disparity between fundamental material design and real-world water treatment uses.