The Adsorption and Sensing Performances of Ir-modified MoS₂ Monolayer toward SF₆ Decomposition Products: A DFT Study

In this paper, the Ir-modified MoS₂ monolayer is suggested as a novel gas sensor alternative for detecting the characteristic decomposition products of SF₆, including H₂S, SO₂, and SOF₂. The corresponding adsorption properties and sensing behaviors were systematically studied using the density functional theory (DFT) method. The theoretical calculation indicates that Ir modification can enhance the surface activity and improve the conductivity of the intrinsic MoS₂. The physical structure formation, the density of states (DOS), deformation charge density (DCD), molecular orbital theory analysis, and work function (WF) were used to reveal the gas adsorption and sensing mechanism. These analyses demonstrated that the Ir-modified MoS₂ monolayer used as sensing material displays high sensitivity to the target gases, especially for H₂S gas. The gas sensitivity order and the recovery time of the sensing material to decomposition products were reasonably predicted. This contribution indicates the theoretical possibility of developing Ir-modified MoS₂ as a gas sensor to detect characteristic decomposition gases of SF₆.