Nitrogen-doped graphene as an excellent candidate for selective gas sensing

The toxic gases, such as CO and NO, are highly dangerous to human health and even cause the death of person and animals in a tiny amount. Therefore, it is very necessary to develop the toxic gas sensors that can instantly monitor these gases. In this work, we have used the first-principles calculations to investigate adsorption of gases on defective graphene nanosheets to seek a suitable material for CO sensing. Result indicates that the vancancy graphene can not selectivly sense CO from air, because O₂ in air would disturb the sensing signals of graphene for CO, while the nitrogen-doped graphene is an excellent candidate for selectivly sensing CO from air, because only CO can be chemisorbed on the pyridinic-like N-doped graphene accompanying with a large charge transfer, which can serve as a useful electronic signal for CO sensing. Even in the environment with NO, the N-doped graphene can also detect CO selectively. Therefore, the N-doped graphene is an excellent material for selectively sensing CO, which provides useful information for the design and fabrication of the CO sensors.