2D NbS2 monolayer as a gas sensor for the detection of nitrogen-containing toxic gases

Nitrogen-containing toxic gases have garnered significant attention due to their adverse effects on human health and the environment. Accurately detecting the presence of these toxic gases has become a major challenge. This paper investigates the potential of 1T-NbS2 and 2HNbS2 monolayers as sensor materials for nitrogen-containing toxic gases by using density functional theory. The stability of these monolayers is confirmed through kinetic and thermodynamic calculations, and the most prominent adsorption sites for three types of gases are identified among the six possible adsorption sites on both monolayers. The charge density difference and Bader charge indicate that the maximum charge transfer is observed after the NO molecules are adsorbed on two monolayers (0.235 and 0.157 e). In addition, the shorter recovery times of NH3 (9.7 × 10−8 s) and NO2 (1.0 × 10−4 s) on the 2HNbS2 monolayer identify NbS2 monolayer as a promising sensor material for these toxic gases. The practical significance of using NbS2 monolayer as a sensor material is confirmed by examining the humidity effect and transmission characteristics using an electrode model. I-V curve reflects the significant sensitivity of 1T-NbS2 and 2HNbS2 monolayers to NO2 molecules. These results confirm NbS2 monolayers are a promising sensor material for NO2 and NH3 molecules, with potential applications in environmental protection, industrial safety, and healthcare. [Display omitted]