Sharkas Kamal, Wong Bryan M
Department of Chemistry, Department of Physics & Astronomy, and Materials Science & Engineering Program, University of California-Riverside, Riverside, California 92521, United States.
Environ Sci Technol Lett. 2025 Feb 3;12(2):230-236. doi: 10.1021/acs.estlett.4c01130. eCollection 2025 Feb 11.
Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants found in groundwater sources and a wide variety of consumer products. In recent years, electrochemical approaches for the degradation of these harmful contaminants have garnered a significant amount of attention due to their efficiency and chemical-free modular nature. However, these electrochemical processes occur in open, highly non-equilibrium systems, and a detailed understanding of PFAS degradation mechanisms in these promising technologies is still in its infancy. To shed mechanistic insight into these complex processes, we present the first constant-electrode potential (CEP) quantum calculations of PFAS degradation on electrified surfaces. These advanced CEP calculations provide new mechanistic details about the intricate electronic processes that occur during PFAS degradation in the presence of an electrochemical bias, which cannot be gleaned from conventional density functional theory calculations. We complement our CEP calculations with large-scale molecular dynamics simulations in the presence of an electrochemical bias to provide time scales for PFAS degradation on electrified surfaces. Taken together, our CEP-based quantum calculations provide critical reaction mechanisms for PFAS degradation in open electrochemical systems, which can be used to prescreen candidate material surfaces and optimal electrochemical conditions for remediating PFAS and other environmental contaminants.
全氟和多氟烷基物质（PFAS）是在地下水源和多种消费品中发现的持久性环境污染物。近年来，用于降解这些有害污染物的电化学方法因其效率和无化学物质的模块化性质而备受关注。然而，这些电化学过程发生在开放的、高度非平衡的系统中，对于这些有前景的技术中PFAS降解机制的详细理解仍处于起步阶段。为了深入了解这些复杂过程的机理，我们展示了首次关于PFAS在带电表面降解的恒电极电位（CEP）量子计算。这些先进的CEP计算提供了关于在存在电化学偏压的情况下PFAS降解过程中发生的复杂电子过程的新机理细节，而这些细节无法从传统的密度泛函理论计算中获得。我们在存在电化学偏压的情况下，通过大规模分子动力学模拟对CEP计算进行补充，以提供PFAS在带电表面降解的时间尺度。综合来看，我们基于CEP的量子计算为开放电化学系统中PFAS的降解提供了关键的反应机制，可用于预先筛选用于修复PFAS和其他环境污染物的候选材料表面和最佳电化学条件。
