Adsorption of sulfur-containing contaminant gases by pristine, Cr and Mo doped NbS2 monolayers based on density functional theory

Abstract

The adsorption and sensor performance of hazardous gases containing sulfur (SO2, H2S and SO3) on pristine, Cr and Mo doped NbS2 monolayers (Cr-NbS2 and Mo-NbS2) were investigated in detail based on density functional theory. The comparative analysis of the parameters such as density of states, adsorption energy, charge transfer, recovery time and work function of the systems showed that the pristine NbS2 monolayer have poor sensor performance for sulfur-containing hazardous gases due to weak adsorption capacity, insignificant charge transfer and insignificant changes in electronic properties after gas adsorption on the surface. After doping with Cr atoms, the adsorption performance of Cr-NbS2 was significantly improved, and it can be used as a sensor for SO2 and H2S gases and as an adsorbent for SO3 gas. The adsorption performance of Mo-NbS2 is also significantly improved by doping with Mo atoms, and it can be used as a sensor for H2S gas and as an adsorbent for SO2 and SO3 gas. Therefore, Cr-NbS2 and Mo-NbS2 are revealed to be sensing or elimination materials for the harmful gases containing sulfur (SO2, H2S and SO3) in the atmosphere.