Adsorption of diatomic molecules on nitrogenated holey graphene: Theoretical insights

Abstract

Physical adsorption of three diatomic molecules (H2, CO, and HF) on graphene and recently synthesized N-doped holey graphene (4N-graphene) has been studied by using a set of theoretical methods to reveal peculiarities of their non-covalent interactions. Adsorption of hydrogen molecules shows approximately doubled interaction energies (Eint) for 4N-graphene compared with pristine one. At the same time, the CO molecule also shows considerable enhancements in Eint values for physisorption on 4N-graphene. The most significant advantage can be observed for the HF molecule. We connect the nearly ten times enhancement with the occurrence of the tetrafurcated bond. Ab initio molecular dynamics simulations witness that at T=77 K, CO and HF molecules remain at the position nearly the pore during the whole course of simulation. It confirms the potential usage of 4N-graphene as a candidate for gas storage. The present work, which observes the prospective model system, can propose a simple way of describing the complicated events that occur in doped pore regions of graphene-based adsorbents.