Photo-induced degradation of PFASs: Excited-state mechanisms from real-time time-dependent density functional theory
Photo-induced degradation of PFASs: Excited-state mechanisms from real-time time-dependent density functional theory
复制标题
光诱导的 PFAS 降解：来自实时时间依赖密度泛函理论的激发态机制
DOI：
10.1016/j.jhazmat.2021.127026
复制
发表时间：
2022
影响因子：
13.6
通讯作者：
Wong, Bryan M.
中科院分区：
文献类型：
--
作者：
Yamijala, Sharma S.R.K.C.;Shinde, Ravindra;Hanasaki, Kota;Ali, Zulfikhar A.;Wong, Bryan M.
全氟烷基物质和多氟烷基物质 (PFAS) 是饮用水源中发现的危险、致癌和生物累积性污染物。为了减轻和消除这些持久性污染物，最近的实验工作集中在光诱导过程上，以加速其降解；然而，这些有希望的降解过程的机制细节仍不清楚。为了深入了解这些电子激发态过程，我们首次使用激发态、实时时间相关密度泛函理论 (RT-TDDFT) 计算对显式溶剂化 PFAS 的光诱导降解进行研究。此外，我们的大规模 RT-TDDFT 计算表明，通过启用仅解离 Csingle bondF 键的电荷转移过程，同时保持周围水分子完整，这些光诱导的激发可以具有高度选择性。总的来说，这项工作中使用的 RT-TDDFT 技术 (1) 提供了一种新的能力，可以探测光诱导机制，而这是传统基态 DFT 计算无法收集到的；(2) 为理解正在进行的实验提供了基本原理，这些实验正在积极探索 PFAS 和其他环境污染物的光诱导降解。
Per- and polyfluoroalkyl substances (PFASs) are hazardous, carcinogenic, and bioaccumulative contaminants found in drinking water sources. To mitigate and remove these persistent pollutants, recent experimental efforts have focused on photo-induced processes to accelerate their degradation; however, the mechanistic details of these promising degradation processes remain unclear. To shed crucial insight on these electronic-excited state processes, we present the first study of photo-induced degradation of explicitly-solvated PFASs using excited-state, real-time time-dependent density functional theory (RT-TDDFT) calculations. Furthermore, our large-scale RT-TDDFT calculations show that these photo-induced excitations can be highly selective by enabling a charge-transfer process that only dissociates the Csingle bondF bond while keeping the surrounding water molecules intact. Collectively, the RT-TDDFT techniques used in this work (1) enable a new capability for probing photo-induced mechanisms that cannot be gleaned from conventional ground-state DFT calculations and (2) provide a rationale for understanding ongoing experiments that are actively exploring photo-induced degradation of PFASs and other environmental contaminants.