Force Field Based MM2 Molecule-Surface Binding Energies for Graphite and Graphene

Abstract

The gas phase adsorption of 118 organic molecules on graphite and graphene was studied by calculating their molecule surface binding energies, Ecal*, using molecular mechanics MM2 parameters. Due to the general lack of reported experimental binding energy values for organic molecules with graphene, E*(graphene), it was considered desirable to have a simple but effective method to estimate these values. Calculated binding energy values using a three-layer model, Ecal*(3), were compared and correlated to published experimental values for graphitic surfaces, E*(graphite). Pub-lished values of experimental binding energies for graphite, E*(graphite), were available from gas-solid chromatogram-phy in the Henry’s Law region over a range of temperature. Calculated binding energy values using a one-layer model, Ecal*(1), were compared to the three-layer Ecal*(3) values and found to consistently be 93.5% as large. This relation along with an E*(graphite) and Ecal*(3) correlation was used to develop a means to estimate molecule-graphene bind-ing energies. Using this approach we report estimated values of 118 molecule-graphene binding energy values.