Characterization of Pt- or Pd-doped graphene based on density functional theory for H 2 gas sensor

The electronic structure characteristics of Pt1-, Pt2-, Pt3- and Pd1-doped graphene were investigated by first-principles calculations based on density functional theory (the subscript represents the number of dopant atoms). It is found that either Pt or Pd atom can improve the conductivity of graphene, while the stability of Pt doping is better than that of Pd. The conductivity of graphene is also improved by increasing the doping concentration. However, the stability of doped graphene decreases with the increase of doping concentration. Pt1- and Pt2-doped graphene can achieve a good compromise between the stability and electrical conductivity. The adsorption states of H2 on pristine, Pt1- and Pt2-doped graphene were also calculated. The results showed that Pt1-doped graphene can be the best choice to realize the applications of hydrogen-adsorbed graphene.