Comparative DFT study on the H2 adsorption and the sensing properties of BN-, BP-, AlN-, and AlP-decorated graphene nanoflakes

Abstract

In this research, the application of BN, BP, AlN, and AlP edge-doped graphene nanoflakes as sensor for sensing of H 2 molecule was studied by DFT approach. The M06-2X/6-311G++(d,p) level of theory have been used in the calculations. The results showed that the adsorption of H 2 molecule on the BN, BP, and AlN was very weak (−0.97, −0.16, and −1.14 kcal.mol −1 , respectively). By considering the acceptable adsorption of H 2 molecule on the AlP-doped graphene with −5.03 kcal.mol −1 , further calculations were performed on this sheet. Upon adsorption of H 2 molecule, the HOMO–LUMO gap ( E g ) of the AlP-doped graphene nanoflake decreased slightly from 2.01 to 1.92 eV. Therefore, the electrical conductivity of AlP-doped graphene sheet increased. Moreover, Δ H ad = −3.38 kcal.mol −1 and Δ G ad = −1.38 kcal.mol −1 show that the adsorption of H 2 molecule on the AlP-doped graphene is an exothermic and spontaneous phenomenon at room temperature. The NCI-RDG analyses verifies the presence of vdW interactions between H 2 molecule and the AlP-doped graphene. Finally, according to the very low recovery time as 4.65 ns, AlP-doped graphene might be utilized as an effective and fast sensor for H 2 molecule at room temperature. • The effect of BN, BP, AlN, and AlP edge doping of graphene on the H 2 sensing is studied. • Adsorption of H 2 molecule on the AlP-edge doped graphene occurs thermodynamically effective. • NCI-RDG analysis shows that the H 2 adsorption on the AlP-edge doped graphene occurs via vdW interactions. • AlP-edge doped graphene can be considered as an ultrafast H 2 sensor with 4.65 ns recovery time.