▎ 摘　　要

The interaction of CH4 gas molecule on pure graphene and Al, B, N, P doped mono-vacancy graphene by using the density functional theory (DFT) to explore their potential applications as gas sensors. The results demonstrate that the system of Al doped mono-vacancy graphene is the most stable, and Al-doped mono-vacancy graphene performs the largest adsorption energies upon CH4 with the most appreciable effects on the electronic structures. In addition, the adsorption of CH4 can largely enhance the conductivity of these graphene. In summary, we believe that the Al-doped mono-vacancy graphene could be a promising candidate material for the CH4 gas sensors.