Adsorption and gas-sensing properties of Pt2–GaNNTs for SF6 decomposition products

[Display omitted] •It is the first time that Pt2-GaNNTs is used as a gas sensing material for detecting the partial discharge fault in GIS.•Pt2-GaNNTs exhibits good sensitivity and selectivity to the decomposition products of SF6.•Pt2-GaNNTs supports a new way to on-line detecting the partial discharge in GIS. Partial electric discharge faults in gas-insulated switchgear (GIS) seriously affect the operational stability of power systems. In this study, H2S, SO2, SO2F2, and SOF2 were selected as characteristic SF6 decomposition products to characterize the partial electric discharge faults in a GIS. Pt cluster-modified gallium nitride nanotubes (Pt2–GaNNTs) were selected as the gas-sensing material to study their adsorption and gas-sensing performance for SF6 decomposition products H2S, SO2, SO2F2, and SOF2. Calculation results showed that Pt2 clusters presented stable doping structures on GaNNTs that greatly enhanced the surface activity for gas adsorption. The adsorption structures, adsorption energy, charge transfer, energy band, density of states, and molecular orbit were analyzed on the basis of density functional theory. Gas molecules formed stable structures on the surfaces of Pt2–GaNNTs through chemical adsorption. The order of adsorption ability was SO2 > H2S > SOF2 > SO2F2, and that of gas-sensing ability was SOF2 > SO2 > H2S > SO2F2. In this article, a new method to detect the partial electric discharge in GIS is proposed. The proposed method helps enhance the running stability of GIS.