Effect of noble metal atoms on adsorption and electronic properties of graphene toward toxic gas

Abstract

The effect of Pd and Pt atoms on the adsorption properties of graphene toward CO, H2S, and SO2 gas molecules are investigated using the density functional theory (DFT). The optimal adsorption configurations, adsorption energy, and electronic properties of Pd and Pt atom doped and decorated graphene after adsorbing CO, H2S, and SO2 are systematically discussed. The CO, H2S, and SO2 gas molecules are chemically adsorbed onto Pd and Pt atom decorated graphene. Their adsorption energies are in the range of −1.285 to −3.028 eV. However, for Pd and Pt doped graphene, the adsorption energies of three gas molecules are changed (−0.838 to −1.402 eV). Take CO as an example, the adsorption energy of CO on Pd and Pt decorated graphene are −2.013 eV and −3.028 eV, respectively, which is larger than that of CO on Pd and Pt doped graphene. Moreover, Pt decorated graphene is more sensitive for three gas molecules than other cases. These results indicate that the adsorption properties of graphene can be further improved by Pd and Pt atom doping and decoration, which provides some theoretical guidance for the experimental study of graphene-based gas sensors.