Ultra-sensitive electroanalysis of toxic 2,4-DNT on o-CoxFe1-xSe2 solid solution: Fe-doping-induced c-CoSe2 phase transition to form electron-rich active sites

Xu Xia; Zheng Liu; Qian-Qian Xu; Xing-Liang Cheng; Jun-Jie Li; Shan-Shan Li

doi:10.1016/j.aca.2022.340291

Ultra-sensitive electroanalysis of toxic 2,4-DNT on o-Co_xFe_1-xSe₂ solid solution: Fe-doping-induced c-CoSe₂ phase transition to form electron-rich active sites

Anal Chim Acta. 2022 Sep 22:1227:340291. doi: 10.1016/j.aca.2022.340291. Epub 2022 Aug 22.

Authors

Xu Xia¹, Zheng Liu¹, Qian-Qian Xu², Xing-Liang Cheng¹, Jun-Jie Li¹, Shan-Shan Li³

Affiliations

¹ Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, School of Physics and Electronic Information, Huaibei Normal University, Huaibei, 235000, PR China.
² Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, PR China.
³ Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, School of Physics and Electronic Information, Huaibei Normal University, Huaibei, 235000, PR China. Electronic address: sa157002@mail.ustc.edu.cn.

PMID: 36089310
DOI: 10.1016/j.aca.2022.340291

Abstract

How to achieve the sensitive electroanalysis of organics pollution in water environment is vital significance, but it is limited by their redox inert and the ambiguous detection mechanism. Herein, Fe-doping-induced structural phase transition engineering is designed to make the cubic (c-) CoSe₂ to orthorhombic (o-) CoSe₂, accompanying with the formation of o-Co_xFe_1-xSe₂ solid solution. By controlling the Fe doping amount, the fully orthogonalized C1F1 (the mole ratio of Co/Fe is 1:1) electrode acquires a high sensitivity of 0.293 μA μM^-1 toward 2,4-Dinitrotoluene (2,4-DNT) detection. Besides, C1F1 exhibits excellent stability, reproducibility and practicality for 2,4-DNT detection. Combined with experimental studies and theoretical calculations, it is shown that during the phase transition, electrons are transferred from Co to Fe, forming electron-rich Fe active sites. The Fe sites can match well with free 2,4-DNT molecules and then accelerate the reduction process of 2,4-DNT. A series of experiments including DFT and electrochemistry demonstrate that the doping-induced structural phase transition strategy can improve the adsorption performance of the material and also enhance the catalytic ability, thereby enhancing the electrochemical sensitivity. The co-engineering of morphology and phase transition of metal selenides by doping will provide inspiration for the design of sensitive sensing interfaces for organic pollutants.

Keywords: CoSe(2); DFT; Electrochemical detection of 2,4-DNT; Electron-rich Fe sites; Fe doping induced phase transition.

MeSH terms

Catalytic Domain
Dinitrobenzenes*
Electrons*
Reproducibility of Results

Substances

Dinitrobenzenes
2,6-dinitrotoluene