Investigating the electrochemical advanced oxidation mechanism of N-doped graphene aerogel: Molecular dynamics simulation combined with DFT method

Zhuang Chen; Yimei Zhang; Wenwen Gu; Mingwang Yang; Kaiwen Yao; Ting Cao; Shuai Li

doi:10.1016/j.envres.2022.115198

Investigating the electrochemical advanced oxidation mechanism of N-doped graphene aerogel: Molecular dynamics simulation combined with DFT method

Environ Res. 2023 Mar 1:220:115198. doi: 10.1016/j.envres.2022.115198. Epub 2022 Dec 30.

Authors

Zhuang Chen¹, Yimei Zhang², Wenwen Gu³, Mingwang Yang³, Kaiwen Yao⁴, Ting Cao³, Shuai Li³

Affiliations

¹ School of Water Resources and Hydropower Engineering, North China Electric Power University, Beijing, 102206, China.
² MOE Key Laboratory of Resources and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, China; Laboratory of Environmental Remediation and Functional Material, Suzhou Research Academy of North China Electric Power University, Suzhou, Jiangsu, 215213, China. Electronic address: zhangym@ncepu.edu.cn.
³ MOE Key Laboratory of Resources and Environmental System Optimization, College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, China.
⁴ School of Water Resources and Hydropower Engineering, North China Electric Power University, Beijing, 102206, China. Electronic address: kwyao@ncepu.edu.cn.

PMID: 36592814
DOI: 10.1016/j.envres.2022.115198

Abstract

Nitrogen-doped graphene as a perfectly-efficient and environmentally compatible electrocatalyst won widespread attention in electrochemical advanced oxidation processes (EAOP). However, the relationship between surface structure regulation and activity of catalysts is still lacking in systematic scientific guidance. Herein, nitrogen-doped graphene aerogel (NGA) was conveniently prepared through hydrothermal treatment, and then utilized to fabricate the gas diffusion electrode (GDE) as the cathode for tetracycline (TC) removal. High free radical yield (81.2 μM) and fast reaction rate (0.1469 min^-1) were found in NGA system. The molecular dynamics simulation (MD) results showed that the interaction energy of NGA was greater than the raw graphene aerogel (GA). The adsorption activation of H₂O₂ and the degradation of TC occurred in the first adsorption layer of catalysts, and both processes turned more orderly after nitrogen doping. Moreover, the van der Waals interaction was stronger than the electrostatic interaction. Density function theory (DFT) revealed that the adsorption energy of H₂O₂ at graphitic N, pyridinic N, and pyrrolic N sites was -0.03 eV, -0.39 eV, and -0.30 eV, respectively. Pyridinic N sites were inferred as the main functional regions of in-situ activation •OH, there were more likely to occur ectopic reaction in pyrrolic N, and graphitic N were responsible for improving H₂O₂ production. By revealing the microstructure and activation characteristics of NGA, an experiment-simulation complementary strategy is provided in the EAOP to discover or to optimize new catalysts.

Keywords: Density function theory; H(2)O(2); Molecular dynamics simulation; Nitrogen-doped graphene aerogel; Tetracycline.

Publication types

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

MeSH terms

Anti-Bacterial Agents
Graphite* / chemistry
Hydrogen Peroxide
Molecular Dynamics Simulation
Nitrogen
Oxidation-Reduction
Tetracycline

Substances

Graphite
Hydrogen Peroxide
Anti-Bacterial Agents
Tetracycline
Nitrogen