Structure of rutile TiO2 photocatalytic interfaces

This article summarizes the quantitative structure determinations of rutile TO 2 surfaces and their interfaces with water. These represent model interfaces for photocatalysis, in particular for water splitting. We include a description of the clean surfaces and interfaces of (110) and (011) substrates prepared by standard ultra-high vacuum methods as well as by wet chemical methods. The latter studies allow more realistic environments to be probed of relevance to applications such as self-cleaning windows. In all cases studied, the surfaces have a hydroxyl in the contact layer, with a Ti–OH bond distance of about 1.94 Å. For the formation of OH on the (110) substrate, density-functional theory calculations point to the involvement of Ti interstitials and an aerobic environment.