Efficient degradation of per- and polyfluoroalkyl substances on plasmonic surfaces with visible light

Abstract

Drinking water with per- and polyfluorosubstances (PFAS) contaminants poses serious public health risks, prompting intensive efforts to develop effective remediation strategies. Among these, photodegradation processes are particularly promising because of their efficiency and intrinsic environmental friendliness. However, the experimental identification of suitable photoactive materials and a detailed understanding of the underlying reaction mechanisms are challenging because of the inherent complexity of these excited-state processes. Using our recently developed real-time electron-nuclear dynamics approach (Xu et al., 2024), we demonstrate efficient photoinduced degradation of perfluorooctanoic acid (PFOA) on a plasmonic Au(111) surface with visible light at 530 nm. Our approach enables large-scale simulations (containing over 400 atoms) beyond conventional quantum calculations, which are required to capture the complex photo-induced degradation dynamics in realistic aqueous environments. In particular, our results highlight a complex interplay of collective excitations between the Au(111) surface and adsorbed PFOA molecule, where the surrounding water molecules play an active role in charge transfer that drives the degradation process. Our photo-induced dynamics approaches highlight the utility of plasmonic surfaces and water for efficient PFAS degradation; moreover, these predictive calculations can be used to prescreen candidate material surfaces, solvents, and photocatalytic conditions to remediate PFAS and other environmental contaminants.Environmental Implication: Our time-resolved electron-nuclear dynamics simulations reveal that the plasmonic Au(111) surface is an effective photoactive material that can enable PFOA degradation with visible light (530 nm). Moreover, our results surprisingly show that the surrounding water molecules are not merely spectators in the degradation process and actively participate to enhance charge transfer and promote PFOA decomposition.