Surface reconstructions of TiO2(110) driven by suboxides

Scanning tunneling microscopy and density functional theory are used to develop a new structural model for surface reconstructions driven by Ti interstitials on TiO2(110). Ti interstitials form the edge- or face-sharing octahedra that serve as building blocks for (1x1) reconstruction. Thus, contrary to conventional wisdom, the 1x1 periodicity is insufficient to establish the correct surface stoichiometry. Furthermore, in our structural and compositional model the reversible oxidation or reduction between (1x1) and (1x2) is entirely achieved by transfer of the added rows.