First-principles study on sum-frequency generation spectroscopy of methanol adsorbed on TiO2(110) surface: Effects of substrate and molecular coverages
Journal
Journal of Chemical Physics
Journal Volume
150
Journal Issue
18
Pages
184112
Date Issued
2019
Author(s)
Abstract
In this work, starting from the general theory of sum-frequency generation (SFG), we proposed a computational strategy utilizing density functional theory with periodic boundary conditions to simulate the vibrational SFG of molecules/solid surface adsorption system. The method has been applied to the CH3OH/TiO2(110) system successfully. Compared with the isolated molecule model, our theoretical calculations showed that the TiO2 substrate can significantly alter the second-order susceptibilities of a methanol molecule which is directly related to the SFG intensity. In addition, the SFG spectra have obvious changes while the methanol coverage increases, especially for the OH vibration peaks. Our theoretical spectra agree reasonably well with experimental measurements at 1 ML coverage, and an interesting peak which is absent in the theoretical spectra is tentatively assigned to some CH3 stretch vibration of methanol adsorbed on the oxygen vacancy of TiO2. ? 2019 Author(s).
SDGs
Other Subjects
Calculations; Computation theory; Interferometry; Methanol; Molecules; Titanium dioxide; Computational strategy; First-principles study; Periodic boundary conditions; Second-order susceptibility; Sum frequency generation; Sum-frequency generation spectroscopy; Theoretical calculations; Theoretical spectra; Density functional theory
Type
journal article