Gas Adsorption and Separation in Realistic and Idealized Frameworks of Organic Pillared Graphene: A Comparative Study

In this work, we present a systematic
and thorough comparison between
gas adsorption and energy storage properties in idealized or realistic
models of organic-pillared reduced-graphene-oxide sheets. First, atomistic
simulations based on density functional theory are used to generate
the structures of these novel systems. Second, Grand Canonical Monte
Carlo is used to predict the adsorption properties of the proposed
frameworks in the case of two different gases, notably hydrogen and
carbon dioxide. While one can safely conclude that gas adsorption
is strongly affected by the density of the pillars and the chemical
composition of the compounds, a comparison between realistic idealized
structures shows that even the corrugation of graphene sheets has
a deep impact on such properties. Finally, we produce evidence of
the potentiality of these pillared structures to be used as gas separation
devices by investigating the sieving of an equimolar CO2/H2 mixture at room temperature.