Effects of Pt and Au adsorption on the gas sensing performance of SnS 2 monolayers: A DFT study

In the framework of density functional theory approach, we have reported on the results of the adsorption of some small gas molecules on the Auand Pt-adsorbed SnS2 monolayers. The changes in the electronic properties of SnS2 monolayers were evaluated upon introducing Pt and Au adatoms. For this purpose, we firstly assessed the atomic configurations, and electronic properties of Pt-SnS2 and Au-SnS2 systems, and then surveyed the gas molecules (COx, NOx, NH3) interaction with Pt-SnS2 and Au-SnS2 systems. The van der Waals (vdW) interactions were included to obtain the most stable geometrical structures of Ptand Au-functionalized SnS2 monolayers with adsorbed gas molecules. By comparing the adsorption energies of Pt-SnS2 and Au-SnS2 systems towards gas detection with those of perfect ones, we found that the process is energetically stable on the Ptand Au-adsorbed systems. The charge density difference plots also showed that the electronic properties of Ptand Au-adsorbed SnS2 systems were influenced by gas adsorption. Our results demonstrated that the considered gas molecules were strongly chemisorbed on the Pt-SnS2 and Au-SnS2 systems, implying the potential of these metal embedded systems in the applications of sensing device for COx, NOx, and NH3 detection.

Automated summary

In this study, the adsorption of small gas molecules on Au and Pt-adsorbed SnS2 monolayers was investigated using density functional theory. The results showed strong chemisorption of the considered gas molecules on the Pt-SnS2 and Au-SnS2 systems, indicating potential applications in gas detection.