Gas-sensing simulation of single-walled carbon nanotubes applied to detect gas decomposition products of SF6 in PD

Abstract

Chemical products detection and analysis has been demonstrated as a powerful diagnosis method for SF6 gas-insulated switchgear (GIS). In this paper, Materials Studio software was used to simulate single-walled carbon nanotube (SWNT) detecting gas decomposition products of SF6 in partial discharge (PD). The simulation results show SWNT was the most sensitive to SO2F2 among the gas decomposition products of SF6. SO2F2 molecules adsorbed on SWNT not only obviously changed electronic structures of SWNT, increasing the density of states (DOS) near Femi level, but also greatly reduced the energy gap of SWNT, enhancing its electrical conductivity. However, SWNT is insensitive to HF, H2S and CF4 molecules because its properties were hardly changed when HF, H2S and CF4 molecules were adsorbed on SWNT. Although SO2 and SOF2 molecules adsorbed on SWNT have changed the properties of SWNT to some extent, SO2 and SOF2 cannot be respectively detected by SWNT due to the cross-sensitivity between them.