Adsorption of Nitrogen-ContainingToxic Gases on TransitionMetal (Pt, Ag, Au)-Modified Janus ZrSSe Monolayers for Sensing Applications:A DFT Study

Nitrogen-containing toxic gases (NO, NO₂, and NH₃) are common gases produced in the chemical industry and fuel combustion, which seriously endanger human health and the atmospheric environment. At present, researchers are still exploring the sensing materials for these three gases. Based on density functional theory (DFT), this study uses a Janus ZrSSe monolayer as the substrate and transition metals (Pt, Ag, and Au) for surface modification to study the gas sensitivity characteristics of the TM-ZrSSe (TM = Pt, Ag, and Au) substrate to NO, NO₂, and NH₃ gas molecules. The results show that the structure of TM-ZrSSe is stable, with negative binding energy (from −4.600 eV to −1.699 eV). Compared with the intrinsic ZrSSe monolayer, the gas adsorption energy of the three modified monolayers is greatly improved, and the adsorption distance is enormously reduced, showing that modification of Pt, Ag, and Au atoms enhances the gas sensitivity of ZrSSe for NO, NO₂, and NH₃ molecules. In contrast, the adsorption effect of TM-ZrSSe on the three gases is ranked from high to low as NH₃ > NO₂ > NO. Combined with the recovery time for the analysis, Pt-ZrSSe is a good sensing material for NO and NO₂ and a potential adsorption material for NH₃, while Ag-ZrSSe and Au-ZrSSe are favorable sensing materials for NO and excellent adsorption materials for NO₂ and NH₃. These findings provide an idea for the application of Janus TMDs and the sensing of nitrogen-containing toxic gases (NO, NO₂, and NH₃).