Experimental and density functional theory study of the gas sensing property of Pt and Au doped WS2 to partial discharge gas CO in air switchgear

Abstract

This work aims to investigate the detection performance of WS₂ and its doped gas sensitive materials for carbon monoxide (CO), one of the most important characteristic gases of partial discharge in air switchgear.Its accurate monitoring can be an effective evaluation of the operating condition of air switchgear. Three gas-sensitive materials were synthesized using the hydrothermal method: WS₂, Pt-WS₂, and Au-WS₂. The materials were characterized through XRD, SEM, and XPS, followed by an evaluation of their sensing performance for CO gas. The findings revealed that the gas sensitivity of WS₂ was significantly enhanced through doping with Pt and Au. At a CO concentration of 10 ppm, the response sensitivity of the Pt-WS₂ sensor reached 4.03, while that of the Au-WS₂ sensor was measured at 2.68—both representing an increase by a factor of 3.52 compared to intrinsic WS₂ sensors. Moreover, the response recovery time for the Au-WS₂ sensor was found to be 20–30 s faster than that observed in Pt-WS₂ sensors. The mechanisms underlying the enhancement in CO adsorption on WS₂ due to Pt and Au doping were investigated based on density functional theory calculations encompassing band structure analysis, density of states assessment, adsorption distance measurement, and adsorption energy evaluation. This study posits that both Pt-WS₂ and Au-WS₂ can be used for the detection of partial discharge gas CO in air switchgear.