Rapid communication: Permeability of hydrogen in two-dimensional graphene and hexagonal boron nitride sheets

We study the permeability of atomic hydrogen in monolayer hexagonal boron nitride (h-BN) and graphene using first-principles density functional theory-based simulations. For the specific cases of physisorption and chemisorption, barrier heights are calculated using the nudged elastic band approach. We find that the barrier potential for physisorption through the ring is lower for graphene than for h-BN. In the case of chemisorption, we have studied three specific cases where the H atom passes through by making bonds with the atoms at different sites in the ring. The chemisorption barrier height for graphene is found to be, in general, higher than that of h-BN. We conclude that the dominant mechanism of tunnelling through the graphene sheet and h-BN sheets would be physisorption and chemisorption, respectively.