Per- and polyfluoroalkyl substances (PFAS) are harmful anthropogenic contaminants that pose a severe threat to drinking water resources worldwide. Their remediation is severely impeded by the exceptional strength of C–F bonds and the vast chemical diversity of PFAS compounds, spanning more than 12,000 varieties. Existing degradation strategies typically require harsh thermal or chemical conditions and often result in incomplete defluorination, producing persistent short-chain PFAS byproducts. Here, using first-principles Born–Oppenheimer molecular dynamics simulations, we demonstrate that PFAS molecules undergo spontaneous decomposition on metallic calcium surfaces, driven by calcium’s strong reducing nature. Remarkably, this process is effective across both long- and short-chain PFAS, irrespective of the functional groups. The simulations further reveal the formation of environmentally benign end products, including stable CaF 2, indicating complete defluorination. These findings indicate that a metallic calcium surface is a highly promising candidate for the efficient and complete degradation of PFAS, offering a mechanistically distinct pathway for water remediation.
Nayak et al. (Mon,) studied this question.