First-Principle Calculations of Solvated Electrons at Protic Solvent-TiO2 Interfaces with Oxygen Vacancies

Heterogeneous electron transfer dynamics at molecule-metal or molecule-metal oxide interfaces are a central issue for many fields in surface science. Recent time-resolved two-photon photoemission studies observed electron solvation at protic molecule-metal or -metal oxide interfaces in photoinduced charge transfer processes. Although the solvated electron is expected as a functional state (for instance, highly catalytic active site, promoter of charge transfer at devices), details are not yet well understood because of the strong dependence of specific atomistic-level solvent-substrate interactions on interfaces, e.g., ordered hydrogen. bonds or defects at surfaces. We focus on the interfaces of H2O/TiO2(110) and CH3OH/TiO2(110) and have applied ab initio DFT calculations for several structures with changing coverage and adsorption types and after inserting oxygen vacancies. The electronic structures of wet-electron states and hydrogen bonds at interfaces have been analyzed using the calculated results.