Adsorption of SF6 decomposition gases (SO2 and SOF2) onto pristine and transition metal modified WSe2 monolayers: A systematic DFT study

Abstract

The properties of SF6 characteristic decomposition products (SO2 and SOF2) adsorbed on intrinsic and transition metal atom modified WSe2 monolayers were studied based on the first principles. The adsorption structure, adsorption energy, electron transfer, density of states, electron differential density, work function, and desorption properties are comprehensively discussed. In addition, the charge transfer in the adsorption system was qualitatively analyzed by using the frontier molecular orbital theory and energy band. The results show that the pristine WSe2 monolayer has poor sensing performance for SO2 and SOF2. Effective modification methods can significantly increase the adsorption activity of the monolayer surface. The modification methods of transition metal atom adsorption and doping are discussed respectively. The modified monolayer all exhibit good sensing properties compared to the pristine monolayer due to the significant electronic hybridization between the impurity atoms and the gas molecules. Finally, the recovery response time of gas molecules from transition metal atom modified WSe2 monolayer is evaluated to evaluate its potential application in the detection and removal of fault gases in SF6 insulation equipment. Our work is not only important for predicting novel transition metal sulfide sensing materials, but also provides theoretical guidance for further developing WSe2-based sensors and scavengers for environmental monitoring applications.