CoO-SnSe monolayer: A high potential candidate for SF6 characteristic decomposition gas adsorption and detection.

Insulation performance testing of gas-insulated switchgear (GIS) and treatment of SF 6 decomposition products under partial discharge are two crucial studies. In this paper, the adsorption behavior and sensor properties of five characteristic decomposition gases of SF 6 (HF, H 2 S, SO 2 , SOF 2 , SO 2 F 2) on intrinsic and CoO-doped SnSe monolayers are investigated in detail based on density-functional theory. The results showed that the adsorption behaviors of HF, H 2 S, SOF 2 and SO 2 F 2 on SnSe monolayers were all physisorption among which the best adsorption was SO 2 with an adsorption energy of −0.618 eV, which is a weak chemisorption. After doping with CoO, the adsorption capacity of SnSe monolayer for five gases was significantly enhanced, in which the adsorption energies for SO 2 and SOF 2 reached −1.356 eV and −1.175 eV, respectively. In addition, the conductivity of the system is greatly improved, with the bandgap changing from 1.129 eV to 0 eV. The microscopic mechanism of the interaction of gas molecules with CoO-SnSe monolayers has been revealed by energy band structure (E g), density of states (DOS), Milligan charge analysis (∆ Q) and electrostatic potential. Finally, the sensitivity (S) and desorption time (τ) of the five adsorption systems were calculated to illustrate the macroscopic gas-sensitive properties of the system. This work will help to explore the application of CoO-SnSe monolayers in SF 6 decomposition gas sensing detection and adsorption treatment. [Display omitted] • Doping greatly improves the conductivity of the system, and the adsorption effect of doped system on SO 2 and SOF 2 is significantly improved. • The change of electronic characteristics of doped system is expounded. • The sensing characteristics of adsorption system are calculated, and the possibility of SOF 2 as the target gas for CoO-SnSe sensing device to evaluate GIS insulation performance is explored. [ABSTRACT FROM AUTHOR]