Graphene oxide as a candidate material for natural gas storage: A first principles study

Alternative sources of clean energy will be much in demand in the coming days. To store methane (CH$_4$) in sorbent materials at ambient conditions for on-board vehicular usage, minimum adsorption energy of 18.8 KJ/mol is desirable. In this work, we have investigated methane adsorption on graphene oxide using first principles calculations. To accurately capture the weak interactions between CH$_4$ and the substrate we have included van der Waals interactions in our calculations. We show that the adsorption energy falls within the target range. Careful analysis of the various contributions to the binding shows that the enhancement in adsorption energy on going from graphene to graphene oxide arises from a subtle synergy between various effects.