Computational modeling of wet TiO2 (001) anatase surfaces functionalized by transition metal doping



Titanium dioxide anatase nanostructure is a photocatalyst under UV light. Our objective is to discover proper surface and functionalization, which facilitate the efficiency of photocatalytic water splitting on TiO2 crystals. We set up a periodic model of Ti32O64·8H2O as the neutral structure and expose the (001) crystallographic surface as it is more reactive. Using platinum, cobalt, and ruthenium to dope in the (001) crystallographic surface and get Ti30Me2O64·8H2O, which Me stands for either Pt, Co, or Ru. Based on density functional theory and Perdue Burke Ernzerhof functional (PBE) we calculate and optimize the doped nanostructures using VASP software. Through their density of states, we can analyze the possibility of charge transfer at the crystal surface and compare how the doping elements affect the charge transfer direction. A comparison of the computed absorption spectra and the charge density of the doping nanostructures help us in better understanding of the possibility of the bandgap tuning in photocatalytic energy nanomaterials. © 2012 Wiley Periodicals, Inc.