DFT-based Theoretical Simulations for Photocatalytic Applications Using TiO2

TiO2 has been shown to be a potential candidate for photoinitiated processes, such as dye sensitized solar cells and water splitting in production of H2. The large band gap of TiO2 can be reduced by functionalizing the oxide by adsorbing dye molecules and/or water reduction/oxidation catalysts, by metal/nonmetal doping, and by mixing with another oxide. Due to these methods, several different TiO2‐based complexes can be constructed having different geometries, electronic structures, and optical characteristics. It is practically impossible to test the photocatalytic activity of all possible TiO2‐based complexes using only experimental techniques. Instead, density functional theory (DFT)‐based theoretical simulations can easily guide experimental studies by screening materials and providing insights into the photoactivity of the complexes. The aim of this chapter is to provide an outlook for current research on DFT‐based simulations of TiO2 complexes for dye sensitized solar cells and water splitting applications and to address challenges of theoretical simulations.