(79d) The Role of Redox-Active Metallopolymers in the Selective Remediation of Water from Pfas Contaminants

Per- and polyfluoroalkyl substances (PFAS) are persistent and toxic compounds that are commonly found in water and pose a significant health risk to humans. The conventional methods for capturing PFAS from water suffer from a lack of selectivity, particularly at low concentrations. Here, we introduce electrosorption techniques as a modular, environmentally friendly, and easily scalable approach to enhance the selectivity of PFAS. We employed metallopolymers as electrode materials due to their attractive properties for energy storage and electronic devices. Specifically, we investigated five different metallopolymers with distinct functional groups and electron densities to determine their selectivity towards PFAS compounds. Our results demonstrate that metallopolymers with higher electron density exhibit greater uptake and regeneration efficiency. Notably, PMAECoPF₆ showed the highest affinity towards perfluorooctanoic acid (PFOA), with an uptake of over 90 mg-PFOA/g-adsorbent at 0.0 V vs. Ag/AgCl and a regeneration efficiency of over 85% at -0.4 V vs. Ag/AgCl in one hour of experimentation. Moreover, we observed that the adsorption capacity of metallopolymers was unaffected by the water matrices, including tap water, secondary water effluent, and various salt concentrations. The desorption kinetics further revealed that electrochemical input can increase the regeneration efficiency by >40% compared to the open circuit. Overall, we have developed a metallopolymers-based system that employs electrosorption techniques for selective capture and release of PFAS from water. Our findings provide a promising approach for future water remediation technology, thereby creating a water-energy nexus.