Adsorption behavior of N<inf>3</inf>-CNT towards SF<inf>6</inf> decomposed species: a DFT study

Abstract

Detecting SF 6 decomposed species by chemical gas sensors has been accepted as a workable method to estimate the operation status of insulation devices in electrical engineering. Functioned by N atoms, carbon nanotubes (CNTs) would be provided with enhanced sensitivity and response towards gas molecules due to the high catalytic activity of metal atoms for gas interaction, which has drawn considerable attentions in recent years for gas sensor use. In this paper, the adsorption of two SF 6 decomposed components (SOF2 and SO 2 ) onto N 3 -doped CNT were theoretically studied based on density function theory method. The geometric and electronic behavior of N 3 modified single-walled carbon nanotube (SWCNT) towards adsorption for SF 6 decomposed components were investigated. N 3 decoration exerts great impacts on adsorption of gas molecules onto CNT surface through providing active adsorption sites for CNT support. Results indicated that N 3 embedded SWCNT possesses stronger chemical reactivity towards gaseous molecule adsorption given the higher localization of electron distribution in N 3 center. After adsorption, the conductivity of N 3 -CNT changes with respect to various gas molecules. Thus we assume that this kind of material could be exploited as a novel sensing one for potential preparation as gas sensors for SF 6 decomposed species detection. Our calculations would be helpful to provide first insight into the application of N 3 -SWCNT as gas sensor in SF 6 insulated devices.