Chlorine molecule adsorbed on graphene and doped graphene: A first-principle study

Adsorption of molecular chlorine (Cl2) on intrinsic and B-, Si-, Cr-, Cu-, Fe-, Mn-, Ni-, Ti- and Au-doped graphene was theoretically studied using first-principle approach based on density functional theory in order to develop their potential applications as Cl2 gas sensors. The structural, electronic and magnetic properties of the graphene-molecule adsorption adducts are strongly dependent on the dopants. Cl2 molecule is adsorbed weakly on intrinsic and B-doped graphene; in general, strong chemisorption is observed on Si-, Cr-, Cu-, Fe-, Mn-, Ni-, Ti- and Au-doped graphene. The most stable adsorption geometries, energies, magnetic moments, charge transfers and density of states of these systems are thoroughly discussed. This work reveals that the sensitivity of graphene-based chemical gas sensors for Cl2 can be drastically improved by introducing appropriate dopant, and Ti as well as Au is the best choice among all the dopants.