Modification of graphene as active hydrogen storage medium by strain engineering

From the first principles study, it is shown that chemically inert monolayer graphene becomes active by strain engineering. The sheets are stretched biaxially to introduce strain of 1.43%, 5%, 8.5% and 10% in the C–C bond lengths. The introduction of strain enhances the chemical reactivity of graphene surface and hence they become chemically more active than the pristine one. The interaction of borane and molecular hydrogen increases with increase in strain in the substrate (strained graphene) and these molecules bind with considerable binding energy. Since graphene sheets can be freely suspended without any substrate, we can stretch the sheets by tuning distance between the clamped edges of the holding frame. In this way, stacks of stretched graphene sheets can be manufactured and a good hydrogen storage medium can be obtained. Likewise, one can tailor graphene in such a way to exhibit its multi-faceted applicability by strain engineering.