Graphene-Based gas sensors

Abstract

Here, we have done the Density Functional Theory (DFT) calculations to study the N-based gas (NH3, NO2 and NO) sensing mechanism on both graphene and doped (B, Al, Ga) graphene. Generalized gradient approximation (GGA-PBE) within projector-augmented wave (PAW) methodology is adopted to investigate the electronic properties of these materials. We have calculated the adsorption energy of all these three gases on both pure and doped graphene. We have also plotted the charge density to understand the qualitative distribution of total charges over the atoms. Bader charge analysis is done to get the quantitative idea of the charges on individual atom. The density of states (DOS) is calculated in each case to investigate the electronic property. All the calculations are done in two different doping concentrations to see the effect of doping concentration on the sensing property. We have found that B doping in graphene significantly improves the selective sensing property towards NO2 than other N-based gases like NO and NH3.