Adsorption of small gas molecules onto the two-dimensional Janus SnSSe monolayer

Abstract

First-principles electronic structure calculations under density functional theory (DFT), carbon monoxide (CO), nitrogen monoxide (NO), nitrogen dioxide (NO2), ammonia (NH3), and oxygen gas (O2) has been studied to explain the small gas detection capabilities onto the two-dimensional (2D) Janus SnSSe monolayer considering for each different sites. By including van der Waals (vdW) interactions between gas molecules and SnSSe, we have found that NO, NO2 and NH3 from these proposed molecules could be strongly adsorbed on the SnSSe monolayer with large adsorption energies. The charge transfer variation of electronic structures and the partial density of states are discussed. Thus, our results for the potential applications of the SnSSe monolayer in gas sensing provide a theoretical basis as well as an important explanation for the experimental findings.