Structure and Photo-Induced Charge Transfer of Pyridine Molecules Adsorbed on TiO2(110): A NEXAFS and Core-Hole-Clock Study

Abstract

The structure and photo-induced charge transfer time of pyridine molecules adsorbed on a rutile TiO 2 (110) surface have been studied by near-edge x-ray absorption fine structure (NEXAFS) spectroscopy, density functional theory (DFT) calculations and core-hole-clock (CHC) spectroscopy. Polarization dependence of NEXAFS spectra and geometrical optimization by the DFT calculations revealed that the pyridine molecules are bound to the TiO 2 surface with an upright configuration where the N atom binds to a surface Ti atom. The CHC results indicate that the charge transfer from the LUMO+2 orbital of pyridine with a π* symmetry to the conduction band of TiO 2 is quite fast, where the timescale is less than 3 fs.

Pyridine as a Resonantly Addressable Group to Study Electron-Transfer Dynamics in Self-Assembled Monolayers

“…The quality of the monolayers was however specifically verified in our study by several complementary spectroscopic techniques, providing additionally the necessary information and basic parameters for the RAES–CHC experiments. Note also that apart from the SAM issue, pyridine molecules adsorbed on TiO 2 (110) were studied by the CHC approach, and a quite fast charge transfer from the LUMO + 2 π* orbital of pyridine to the conduction band of TiO 2 was observed …”

“…Note also that apart from the SAM issue, pyridine molecules adsorbed on TiO 2 (110) were studied by the CHC approach, and a quite fast charge transfer from the LUMO + 2 π* orbital of pyridine to the conduction band of TiO 2 was observed. 54…”