Adsorption and Gas Sensing Properties of the Pt₃-MoSe₂ Monolayer to SOF₂ and SO₂F₂

SF₆ acts as an insulation gas in gas-insulated switchgear (GIS), which inevitably decomposes under partial discharge caused by insulation defects. This work is devoted to finding a new gas-sensing material for detecting two characteristic SF₆ decomposition products: SOF₂ and SO₂F₂. The platinum-cluster-modified molybdenum diselenide (Pt₃-MoSe₂) monolayer has been proposed as a gas sensing material. Based on first-principles calculations, the adsorption properties and the mechanism were studied by analyzing the adsorption structures, adsorption energy, charge transfer, density of states, and molecular orbitals. The adsorption ability of Pt₃-MoSe₂ to SO₂F₂ is stronger than that to SOF₂ due to its chemisorption property. The obvious change of conductivity of the adsorption system during the gas adsorption process shows that Pt₃-MoSe₂ is sensitive to both of the gas molecules. In addition, the modest adsorption energy signifies that the gas adsorption process can be reversible, which confirms the feasibility of Pt₃-MoSe₂-based gas sensors. Our calculation suggests that Pt₃-MoSe₂-based gas sensors can be employed in GIS for partial discharge detection.