Sensitivity enhancement of stanene towards toxic SO₂ and H₂S

Adsorption of S-containing gases on pristine, defective, and heteroatom doped stanene is studied for gas sensing applications by van der Waals corrected density functional theory. SO₂ and H₂S gas molecules are found to bind to pristine stanene too weakly to alter the electronic properties sufficiently for efficient gas sensing (binding energy of −0.20 and −0.33 eV, respectively). We demonstrate that vacancies and heteroatom doping can enhance the binding energy to −1.67 and −0.74 eV, respectively. It is found that presence of mono-vacancies, tri-vacancies, and In dopants at low concentrations in stanene results in considerable variations of the electronic properties in contact with S-containing gases, thus transforming stanene into an efficient sensing material.