Hydrogen physisorption on nitrogen-doped graphene and graphene-like boron nitride-carbon heterostructures: a DFT study

This work studies H-2 adsorption onto pristine graphene as well as nitrogen-doped (N-doped) graphene and graphene-like boron nitride-carbon heterostructures (GBNCHs) within the framework of the DFT method. The advantages of doped graphene for hydrogen physisorption are determined using electrostatic potential maps, reduced density gradient, and energy decomposition analyses. The obtained results reveal that nitrogen doping can sufficiently enhance H-2/adsorbent interactions. We have shown that the dispersion interactions play the major role in hydrogen adsorption for all structures studied herein. For N-doped models, the orbital term increases in comparison with pristine graphene, indicating the emerging role of the induction force. For GBNCHs involved, it has been shown that the energy redistribution occurs between the dispersion and orbital terms, although overall adsorption energy is almost the same as in the case of graphene. The present results should definitely broaden our understanding of the mechanisms of hydrogen storage using graphene-like materials.