First-principles investigation of vacancy-defected graphene and Mn-doped graphene towards adsorption of H2S

The effect of vacancy defects and doping Mn atoms on the performance of adsorption between graphene and H2S molecules has been investigated by using first-principles study. The analysis shows that although vacancy defects slightly enhances the adsorption of H2S on graphene, there is no chemical adsorption formed between them. However, after doping graphene with Mn atoms, the adsorption energy and charge transfer between graphene and H2S increase significantly and the maximum values under various adsorption sites and configurations reach 4.3228 eV and 0.171 e, respectively. In addition, the charge density between Mn-doped graphene and H2S molecules is greater than 3.000 × 10−1 e/Å3, and the orbitals of Mn and S atoms are hybridized, indicating a formation of chemical bonds. Therefore, Mn doping can significantly enhance the adsorption of H2S on graphene, improving the sensitivity of graphene to H2S. Mn-doped graphene is expected to be a potential sensing material for making high-performance H2S gas sensors.