First-principles study of Pd-MoSe2 as sensing material for characteristic SF6 decomposition components

Abstract

SF6 decomposition component detection is an effective way to diagnose the severity and type of electric discharge. In this study, MoSe2 based material has been chosen as the gas sensing material for the detection of SOF2 and SO2F2, the two characteristic decomposition components of SF6. Based on density functional theory calculations, the adsorption properties of both SOF2 and SO2F2 on intrinsic and Pd doped MoSe2 are studied by analyzing the adsorption structure, charge transfer, density of states, and molecular orbit. The results show that SOF2 and SO2F2 adsorb on intrinsic MoSe2 by physisorption, resulting in weak gas sensitivity. After Pd doping on MoSe2, it dramatically enhances the gas sensitivity of MoSe2 to SOF2 and SO2F2; both the gases interact with Pd-MoSe2 by chemisorption. In addition, SOF2 and SO2F2 show an increase in conductivity during the adsorption process to different extents. The calculation results show that Pd-MoSe2 can be a potential gas sensing material for SOF2 and SO2F2 detection in SF6-insulated equipment.