Probing the activation mechanism of nitrogen-doped carbonaceous materials for persulfates: Based on the differences between peroxymonosulfate and peroxydisulfate

Jinling Wang; Jingjing Yang; Sijia Liu; Chen Yang; Qian Yang; Zhi Dang

doi:10.1016/j.envpol.2023.121685

Probing the activation mechanism of nitrogen-doped carbonaceous materials for persulfates: Based on the differences between peroxymonosulfate and peroxydisulfate

Environ Pollut. 2023 Jul 15:329:121685. doi: 10.1016/j.envpol.2023.121685. Epub 2023 Apr 20.

Authors

Jinling Wang¹, Jingjing Yang², Sijia Liu¹, Chen Yang³, Qian Yang⁴, Zhi Dang⁵

Affiliations

¹ School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
² Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, 510650, China.
³ School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China. Electronic address: cyanggz@scut.edu.cn.
⁴ Guangdong Provincial Key Lab of Green Chemical Product Technology, School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou, 510640, PR China.
⁵ School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China.

PMID: 37087085
DOI: 10.1016/j.envpol.2023.121685

Abstract

The activation processes of persulfates by metal-free nitrogen-doped carbonaceous material (NCM) remain unclear due to their complex structures and heterogeneous nature. On the other hand, from the perspective of persulfates, it is possible to clarify the reaction between persulfates and NCM by considering the differences in activation behaviors between peroxymonosulfate (PMS) and peroxydisulfate (PDS). Our study aims to compare the differences between NCM-PDS and NCM-PMS using a fully metal-free NCM as a model catalyst. Firstly, NCM-PDS was more efficient than NCM-PMS in degrading phenolic compounds (PCs). Secondly, the stoichiometric ratio between consumed persulfates and DCP removed in the NCM-PDS (0.73) is lower than in the NCM-PMS (1.08). Thirdly, PMS and PDS adsorb on NCM in different ways, suggesting that the peak O-O bond in PDS has blue shifted from 814 cm^-1 to 805 cm^-1, while that of O-O bond in PMS has shifted from 889 cm^-1 to 834 cm^-1. Additionally, the hydrogen bond between the phenolic group and oxidants plays a critical role in PCs degradation by NCM-PDS, exhibiting a stronger pH effect and higher kinetic isotope effects (KIEs) than NCM-PMS. A proton-coupled electron transfer process has been proposed for PCs degradation using NCM-PDS, and a scheme of reaction pathways has been provided for the NCM-PMS/PDS-PCs system. The study results provide a deeper understanding of the activation of persulfates by NCM, as well as a strategy for selecting oxidants.

Keywords: Nitrogen-doped carbonaceous material; Peroxydisulfate (PDS); Peroxymonosulfate (PMS); Proton-coupled electron transfer; Reaction pathway.

MeSH terms

Electron Transport
Metals
Nitrogen*
Oxidants / chemistry
Peroxides* / chemistry

Substances

peroxymonosulfate
Nitrogen
Peroxides
Oxidants
Metals