DFT Exploration of a Pd-Doped InSe Monolayer as a Novel Gas Sensing Candidate upon SF Decomposition: SO, SOF and SOF.

Monitoring SF decomposition gases has emerged as a vital diagnostic technique for evaluating insulation conditions and identifying faults in SF-based electrical equipment. This study comprehensively explores the adsorption properties and sensing capabilities of a Pd-doped InSe (Pd-InSe) monolayer for SF decomposition gases, including SO, SOF, and SOF, through density functional theory calculations. The Pd-InSe monolayer is constructed by substituting one Se atom with a Pd atom in the pristine InSe structure. Then, the Pd doping effect on the InSe monolayer and the adsorption behaviors of the Pd-InSe monolayer for three gases are thoroughly examined. The adsorption configurations, charge density differences, and electron localization functions are scrutinized to elucidate the gas adsorption mechanisms of the Pd-InSe monolayer; and the band structures, along with the density of states, are analyzed to gain insights into the resistive gas sensing mechanisms for detecting these three gases. Finally, the temperature-dependent recovery characteristics are evaluated to assess the reusability of the monolayer. These findings not only underscore the potential of the Pd-InSe monolayer for sensing SF decomposition gases but also open new avenues for the development of next-generation 2D materials in gas sensing applications within the field of electrical engineering.