Study of physisorption of aromatic molecules on hydroxylated α-SiO2 (001) surface using dispersion-corrected density functional theory

In this work, the interactions are investigated in a series of aromatic molecules adsorbed on hydroxylated (001) surface of alpha-SiO2 using density functional theory with dispersion correction. It is observed that the van der Waals interactions are strongly dependent on the kind of aromatic molecules. For the molecules of heavy halogen, it shows the strong interaction compared to that of benzene molecule due to its large electron affinity of aromatic molecules. Oxygen-based aromatic molecules are very active and easily to from weak hydrogen bond with hydroxylated surface at tilted configurations. The interaction can be attributed mainly to the weak hydrogen bond and short-range van der Waals interaction. The magnitude of weak hydrogen bond is comparable with that of van der Waals dispersion interaction of benzene ring at flat configuration. For non-polar aromatic molecules, the flat configuration is more stable due to the strong van der Waals interaction of benzene ring. Newly SCAN-rVV10 functional offers precise description for capturing the medium and long-range van der Waals interaction in adsorbate-surface. This study offers theoretical guideline for the design and application of aromatic-based molecules in the fields of catalysis, tribology and electronic devices.