Insight into the key role of oxygen dopants over ball-milled boron nitride for efficient degradation of PFOS alternative 6:2 fluorotelomer sulfonic acid

Lijie Duan; Jian Wei; Jinshan Wei; Minghao Wang; Yong Wang; Xue Cheng; Mengbin Gu; Xinyi Zhang; Xianghua Wen; Yonghui Song

doi:10.1016/j.jhazmat.2022.130419

Insight into the key role of oxygen dopants over ball-milled boron nitride for efficient degradation of PFOS alternative 6:2 fluorotelomer sulfonic acid

J Hazard Mater. 2023 Mar 5:445:130419. doi: 10.1016/j.jhazmat.2022.130419. Epub 2022 Nov 17.

Authors

Lijie Duan¹, Jian Wei², Jinshan Wei¹, Minghao Wang¹, Yong Wang³, Xue Cheng⁴, Mengbin Gu⁴, Xinyi Zhang⁵, Xianghua Wen⁶, Yonghui Song⁷

Affiliations

¹ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China; School of Environment, Tsinghua University, Beijing, China.
² State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China. Electronic address: weijian0911@163.com.
³ Institute of Environmental Information, Chinese Research Academy of Environmental Sciences, Beijing, China.
⁴ School of Environment, Tsinghua University, Beijing, China.
⁵ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China; College of Water Science, Beijing Normal University, Beijing, China.
⁶ School of Environment, Tsinghua University, Beijing, China. Electronic address: xhwen@tsinghua.edu.cn.
⁷ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China; School of Environment, Tsinghua University, Beijing, China. Electronic address: songyh@craes.org.cn.

PMID: 36455329
DOI: 10.1016/j.jhazmat.2022.130419

Abstract

6:2 Fluorotelomer sulfonic acid (6:2 FTS) has been identified as an alternative to perfluorooctane sulfonic acid but has been proven to cause potential threats to humans and the environment. In this study, boron nitride (BN) photocatalysis was explored for 6:2 FTS degradation with 100% removal (k_obs=1.8 h^-1) and desulfurization rate of 100% as well as the defluorination rate of 57.3%. The superior performance of BN was primarily related to oxygen dopants defects (O-dopants). In addition, O-dopants contribution was confirmed by ball-milled BN (B-BN), which introduced more O-dopants and exhibited an increased 6:2 FTS degradation rate of 2.88 h^-1. The decomposition of 6:2 FTS was attributed to holes (h⁺), hydroxyl radicals (•OH), and superoxide (•O₂-) and proceeded via two pathways, the hydrogen abstraction from ethyl carbons by •OH and the C-S bond activation by h⁺ and •OH. To the best of our knowledge, this is the first study demonstrating that h⁺, •OH, and •O₂^- played significant roles in the heterogeneous photocatalytic degradation of 6:2 FTS.

Keywords: 6:2 fluorotelomer sulfonic acid; Boron nitride; Oxygen dopants; PFAS degradation; Photocatalysis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Boron Compounds / chemistry
Humans
Oxygen*
Sulfonic Acids*

Substances

fluorotelomer sulfonic acids
Sulfonic Acids
boron nitride
Oxygen
Boron Compounds