Single-layer stanane as potential gas sensor for NO2, SO2, CO2 and NH3 under DFT investigation

The monolayer stanane in chair form is reported to be a novel sensor for environmentally toxic and non-toxic gas molecules for the first time. The structure, electronic and vibrational properties of all three possible conformations (chair, stirrup and boat) of stanane are studied in detail using density functional theory (DFT) based on an ab-initio technique. The interactions and charge transfer of environmentally toxic (NO₂, SO₂ and NH₃) and non-toxic (CO₂) gas molecules on the dynamically most stable hexagonal chair type hydrogenated stanene, viz. stanane has been investigated in detail. The most stable configuration, electronic properties, adsorption energies and charge transfer of these gases on stanane are systematically studied and discussed. The band gap of the pure stanane (0.52 eV) is noticed to be changed after interaction with gases. Moreover, the changes in the energy band gap and charge density is observed upon adsorption of NO₂, SO₂, NH₃ and CO₂ gases on p-type stanane based material. The results show that the selectivity of hydrogenated stanene based gas sensors is very important to enhance their sensitivity. It is found that all the gas molecules act as charge donors in which NO₂ gas shows maximum adsorption on the stanane surface along with the maximum charge transfer. The nontrivial affectability and selectivity of stanane demonstrate its potential application in the field of gas sensors and superior impetuses.