Path integral centroid molecular dynamics simulation of para-hydrogen sandwiched by graphene sheets

Abstract

The carbon-hydrogen composite systems of para-hydrogen (p-H2) sandwiched by a couple of graphene sheets have been investigated by means of path integral centroid molecular dynamics simulations at 17K. It has been shown that sandwiched hydrogen is liquid-like but p-H2 molecules are preferably adsorbed onto the graphene sheets because of attractive graphene-hydrogen interaction. The diffusion coefficient of p-H2 molecules in the direction parallel to the graphene sheets is comparable to that in pure liquid p-H2. There exists a characteristic mode of 140cm−1 of the p-H2 molecules, attributed to adsorption-binding motion perpendicular to the graphene sheets.