Si-doped graphene nanosheets as a metal-free catalyst for electrochemical detection of nitroaromatic explosives

Fang Niu; Zhen-Wu Shao; Li-Ming Tao; Yong Ding

doi:10.1016/j.jcis.2021.03.091

Si-doped graphene nanosheets as a metal-free catalyst for electrochemical detection of nitroaromatic explosives

J Colloid Interface Sci. 2021 Jul 15:594:848-856. doi: 10.1016/j.jcis.2021.03.091. Epub 2021 Mar 18.

Authors

Fang Niu¹, Zhen-Wu Shao¹, Li-Ming Tao², Yong Ding³

Affiliations

¹ State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu 730000, China.
² Key Laboratory of Science and Technology on Wear and Protection of Materials, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, Gansu 730000, China. Electronic address: taolm@licp.cas.cn.
³ State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu 730000, China. Electronic address: dingyong1@lzu.edu.cn.

PMID: 33794406
DOI: 10.1016/j.jcis.2021.03.091

Abstract

Si-doped graphene nanosheets (SiGNS) have been successfully constructed via high temperature annealing of graphene oxide and tetraethoxysilane mixture in a sealed glass ampoule. The Si atoms doped into graphene's carbon network mainly existed as C₃-Si-O and C₂-Si-O₂ configurations. The as-prepared SiGNS exhibited excellent electrochemical detection ability to nitroaromatic compounds in 0.1 M phosphoric acid buffer solution (PBS, pH = 8.0) via an electrochemical catalytic process. Five nitroaromatic compounds, including nitrobenzene, 2-nitrotoluene, 4-nitrotoluene, 2, 4-dinitrotoluene and 2, 4, 6-trinitrotoluene, were taken as the analyte to demonstrate the electrochemical catalytic ability of SiGNS. Density functional theory (DFT) calculation was carried out to explore the electrochemical catalytic mechanism of SiGNS. A hydrogen bond mediated electrochemical catalytic mechanism was proposed. Both the excellent electrical conductivity and the rich surface hydroxyl groups enhanced the electrochemical detection ability of SiGNS to nitroaromatic compounds. Si atoms in SiGNS played a key role for the excellent electrochemical detection ability of SiGNS due to most of the surface hydroxyl groups anchored on the Si atoms.

Keywords: Carbon based materials; Electrocatalysis; Metal-free catalyst; Nitroaromatic explosive; Si-doped graphene.