(621by) Understanding Adsorption on the Anatase TiO2 (101) Surface

TiO₂ is an important industrial catalyst, photocatalyst, and catalyst support. When TiO₂ is used as the catalytic substance the reactants must be able to adsorb on to the TiO₂ surface, however, for many small molecules, and by extension substituent groups of large molecules, this does not readily occur and therefore limits the overall reaction rates and usefulness of catalytic TiO₂. For example O₂ does not adsorb on TiO₂, limiting the overall rate of photocatalytic organic pollutant degradation. However, H₂O forms well-ordered monolayers on the surface. To date, there has not been a good, fundamental understanding of why some molecules adsorb to TiO₂ but others do not. In this work we investigate the adsorption of a wide range of small molecules on the anatase TiO₂ (101) surface using density functional theory (DFT) and develop a fundamental description of adsorption on this important surface.