First-principles investigation of Ru-and Pt-doped TiO2 brookite surfaces

Abstract

The electronic structures and optical properties of brookite TiO2 (100) and (110) surfaces doped with transition metals (Ru and Pt) have been investigated by first-principles calculations based on the density functional theory, employing generalized gradient approximation (GGA). The modelled surface structures were constructed from an optimized brookite bulk structure. TiO2 surfaces were doped with transition metals, with one Ti atom replaced by a transition metal atom. The results indicate that doping with both transition metals can narrow the band gap of TiO2, leading to the improvement in the photo reactivity of TiO2. The metal dopants shift the absorption to high wavelengths and improves optical absorbance in the visible and near-IR region. The surface (100) showed higher activity than (110) in both regions.