Influence of surface local structure on photo-induced oxidation reaction of water and competitive sub-reactions on single crystal TiO₂ surface

Abstract

The mechanisms of water photooxidation reaction and sub-reactions (PL emission by recombination with electrons, non-radiative recombination and surface roughening reaction) were investigated using single crystal n-TiO₂ (rutile) electrodes. It was revealed that the reaction efficiency of those competitive processes strongly depends on the atomic level surface local structures, such as Miller index and step-terrace structures. We also revealed that those 4 kinds of reaction processes are highly correlated with each other, indicating that the controlling of the sub reactions is key factor to control the photocatalytic efficiency. The present work has thus opened a new way to investigate the photocatalytic reactivity and stability of these materials on an atomic level, which is important to search for new active materials.