Electronic Properties of Adsorption of CO, CO_2, NH_3, NO, NO_2 and SO_2 on Nitrogen Doped Graphene for Gas Sensor Applications

摘要

The sensitivity of pristine graphene (PG) and nitrogen-doped graphene (N-graphene) toward a series of small gas molecules (CO, CO_2, NH_3, NO, NO_2 and SO_2) has been calculated based on the first principles calculations. The results show that the adsorption of (CO, CO_2, NH_3, NO, NO_2 and SO_2) on PG and N-graphene are weak physisorption with an adsorption energy (E_(ad)) ranging from (-0.115 to 0.640) eV, except the adsorption of (NO_2 and SO_2) on PG are a strong chemisorption. The strong interaction of (NO_2 and SO_2) on PG demonstrating that PG could catalyse or activate, suggesting the possibility of PG as a metal-free catalyst. Moreover, the energy gap (E_g) of PG and N-graphene is opened upon adsorption of (CO, CO_2, NH_3, NO, NO_2 and SO_2) in various ways. Also, the N-graphene with SO_2 gas molecule adsorption has the ability to donating an electron, it needs to a small energy to remove an electron to become a cation. The article demonstrates the feasibility of PG could be a good sensor for (CO, CO_2, NH_3, NO, and NO_2) and N-graphene could be a good sensor for (CO, CO_2, NH_3 and NO).