Photo-induced degradation of PFASs: Excited-state mechanisms from real-time time-dependent density functional theory

Sharma S.R.K.C. Yamijala, Ravindra Shinde, Kota Hanasaki, Zulfikhar A. Ali, Bryan M. Wong*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

21 Citations (Scopus)
29 Downloads (Pure)

Abstract

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 C[sbnd]F 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.

Original languageEnglish
Article number127026
JournalJournal of hazardous materials
Volume423
Issue numberPart A
Early online date25 Aug 2021
DOIs
Publication statusPublished - 5 Feb 2022
Externally publishedYes

Keywords

  • Electronic-excited states
  • Per- and polyfluoroalkyl substances
  • Photo-induced degradation
  • Time-dependent density functional theory

Fingerprint

Dive into the research topics of 'Photo-induced degradation of PFASs: Excited-state mechanisms from real-time time-dependent density functional theory'. Together they form a unique fingerprint.

Cite this