Theoretical screening into Ag-Embedded HfS2 monolayers as gas sensor for detecting SF6 decomposition gases

Abstract

The adsorption properties of Ag embedded HfS2 (Ag-HfS2) monolayers to SF6 decomposition gases (SO2, H2S, HF, SOF2 and SO2F2) were investigated based on density functional theory (DFT). The embedded Ag atoms are stably bound to the sulfur vacancies of the monolayer HfS2, and still maintain the semiconducting properties by analyzing the deformation charge density (DCD), the band structure and the density of states (DOS). The adsorption geometry, charge transfer and DOS of these five gas molecules on Ag-HfS2 monolayer are discussed in detail. The adsorption studies on the gases show that the Ag-HfS2 monolayer has excellent sensitivity for H2S and SO2F2 gases, with adsorption energies of 1.088 and 2.998 eV, respectively. And estimated the gas desorption time in Ag-HfS2 monolayer to screen its application in gas sensitive materials and gas sensors. The results of this study may open up new ideas for researchers to explore highly active HFS2-based two-dimensional nanomaterials.