Ab Initio Modeling of Methanol Interaction with Single-Walled Carbon Nanotubes

Abstract

Equilibrium geometries and binding energies with respect to the interaction of a methanol molecule (MeOH) with single-walled carbon nanotubes (SWCNTs) of various diameter are calculated by means of density-functional theory including an empirical energy correction for dispersion (DFT-D). This theory is validated by comparing DFT-D results for the model systems benzene−MeOH and coronene−MeOH with corresponding results from high-level wave function-based theory. DFT-D potential energy surface (PES) scans along the intermolecular distance using different functionals are compared with spin-component scaled second-order Moller−Plesset perturbation theory (SCS-MP2) energies and reveal a consistent mutual agreement between the two approaches. Hydrogen-terminated tube sections are used to represent the armchair (4,4), (5,5), (6,6), (8,8), and (10,10) SWCNTs. Similar binding energies are found for the armchair (4,4) and the zigzag (7,0) tubes with similar diameter, but the methanol−SWCNT distance is strongly depen...