Effects of Stone-Wales defect on the interactions between NH3, NO2 and graphene.

Using the density functional theory, the interactions between pristine, Stone-Wales defected graphenes (SW-graphene) and two small gas molecules (NH3 and NO2) were investigated and the potential applications of SW-graphene as gas sensors were exploited. Both NH3 and NO2 show weak interactions with pristine graphene. Introducing SW defect into the graphene structure has little effect on the NH3 adsorption, but dramatically enhances the adsorption of NO2 and causes significant deformation of the graphene sheet around the defect site. The strong interaction between NO2 and the SW-graphene also induces dramatic changes to the graphene's electronic structure. This work reveals that the SW-graphene could be an excellent candidate as highly selective sensing material for NO2.