Modeling the Adsorption of Polycyclic Aromatic Hydrocarbons on Graphynes: An Improved Lennard-Jones Formulation

Abstract

Research on the development of theoretical methodologies for modeling noncovalent interactions governing the adsorption of polycyclic aromatic hydrocarbons (PAHs) on graphene and other two-dimensional materials is being intensely pursued in recent times. Highly accurate empirical potentials have emerged as a viable alternative to first-principles calculations for performing large-scale simulations. Herein, we report exploration of the potential energy surfaces for the adsorption of catacondensed and peri-condensed PAHs on graphynes (GYs) using the improved Lennard-Jones (ILJ) potential. Initially, the ILJ potential is parametrized against benchmark electronic structure calculations performed on a selected set of PAH−GY complexes using dispersion-corrected density functional theory. The accuracy of the parametrization scheme is then assessed by a comparison of the adsorption features predicted from the ILJ potential with those computed using electronic structure calculations. The potential energy profiles as well as the single point energy calculations and geometry reoptimizations performed on the minimum-energy configurations predicted by the ILJ potential for a broader range of PAH−GY complexes provided a validation of the parametrization scheme. Finally, by an extrapolation of the PAH adsorption energies on various GYs, we estimated the interlayer cohesion energies for the van der Waals bilayer heterostructures of GYs with graphene to be in the range of 25−50 meV/atom.

Energy landscape of perylenediimide chromophoric aggregates

“…oB97XD was shown to predict the energetics of polyaromatic hydrocarbon aggregates accurately. 34 HOMO orbital isosurfaces were generated after performing single point energy calculations at dimer geometries.…”

Ab initio study of lithium intercalation into a graphite nanoparticle

“…A similar limit was observed with the binding energy PAH adsorbing on to graphene with respect to number of aromatic rings by James and Swathi. 77 We use this limit as a guide for our individual layer size. By more than doubling the C atom count in each sheet, compared to that of Circumcoronene, we are confident that our system is close enough to the limit to exhibit graphite-like binding energies.…”

“…Indeed, it has been shown in a number of theoretical studies that an increased H atom to C atom ratio has a noticeable effect on binding energy. 76,77,101 Given the well-documented sensitivity of the Li intercalation process to the interlayer binding of graphite, deviations are to be expected. We would also expect an experimental OCV to be effected by some of the different environmental factors such as having the experiment be performed at 298.15 K, the use of highly ordered pyrolytic graphite (HOPG), being mixed with carbon binder, being in a functioning lithium half-cell, or being in the presence of a mixture of ethylene carbonate and dimethyl carbonate as electrolyte which leads to the eventual formation of a solid electrolyte interphase Whereas, our simulations occur in a vacuum, for a single nanoparticle of graphite, at 0 K and therefore would not exhibit any environmental effects.…”

“…Indeed, it has been shown in a number of theoretical studies that an increased H atom to C atom ratio has a noticeable effect on binding energy. 76,77,101 Given the well-documented sensitivity of the Li intercalation process to the interlayer binding of graphite, deviations are to be expected. We would also expect an experimental OCV to be…”