Adsorption of O3, SO3 and CH2O on two dimensional SnS monolayer: A first principles study

Highlights: • DFT based study of adsorption of O₃, SO₃, CH₂O, H₂S and HCN gas molecules on the SnS monolayer. • SnS monolayer is more sensitive than MoS₂ towards O₃ and SO₃ molecules. • Electronic properties of SnS monolayer alter significantly after adsorption. • All the studied molecules act as the charge acceptors. -- Abstract: The environment and the health of the masses are being affected by toxic gases such as O₃, SO₃, CH₂O, H₂S and HCN. In this study, we investigate the interaction of such toxic gases on SnS monolayer using density functional theory (DFT). The interaction between species and adsorbent is explained on the basis of their adsorption energy, electronic properties and charge transfer. Our results demonstrate that the process of adsorption of O₃ and SO₃ is chemisorbed in nature whereas CH₂O, H₂S and HCN is physisorbed. The validity of the adsorption process is further confirmed within the frame of electronic properties and charge transfer. As a result, we find each of the investigated gas molecules is acting as a charge acceptor. Diversity in the adsorption of customary gas molecules on the SnS monolayer gives rise to a possibility to exploit them as chemical gas sensors.