High Photoreactivity on a Reconstructed Anatase TiO2(001) Surface Predicted by Ab Initio Nonadiabatic Molecular Dynamics

Anatase TiO2(001) surface with (4 x 1) reconstruction is proposed to be a highly active catalytic surface. In this work, using time-domain ab initio nonadiabatic molecular dynamics, we reveal that the ridge structure formed by anatase(001) surface reconstruction is the photoreactive site for hole migration and trapping. Moreover, the ridge structure is destroyed by low-coverage CH3OH adsorption, leading to the suppression of its high photoreactivity. However, when the CH3OH coverage is increased and intermolecular hydrogen bonds (H-bonds) form, the ridge structure and its high photoreactivity are restored. Furthermore, the hole trapping dynamics is strongly coherent with intermolecular proton transfer in structures with intermolecular H-bonds. Our study proves that anatase TiO2(001)-(4 x 1) is a highly photoreactive surface where the ridge is the photoreactive site for hole trapping, which is coherent with the proton transfer process.