Geometric structure of rutile titanium dioxide (111) surfaces

Understanding the geometric structures of ${\mathrm{TiO}}_{2}$ surfaces at the atomic level is essential for the development of high-performance photocatalysts with desired properties. In this study, first-principles density functional theory calculations have been performed to detect the stable geometric structures of rutile ${\mathrm{TiO}}_{2}{111}$ facets, which are key components of rutile ${\mathrm{TiO}}_{2}$ nanorods for their applications. Based on our theoretical results, the bulk-truncated rutile (111) surfaces with high surface energies can be stabilized through hydroxylation. The stable hydroxylated surface geometries have been rationalized by the photoelectrocatalytic measurements. Using the hydroxylated surface models, some experimental observations of rutile (111) surfaces can therefore be successfully explained.