Doped nano-titania: theoretical insight into structure-property relationships

Doping with metal and non-metal species represents a promising strategy to tailor the optical and electronic properties of semiconducting oxides, such as TiO2. N-doped TiO2 photocatalysts represents a paradigm for such complex systems, where the lattice location of the dopant host and its complex interplay with the material’s crystal structure crucially determine the resulting optical and electronic properties of the material [1-3]. In this study, we investigate the structure-property relationships of N-doped and N,metal-codoped nanocrystalline TiO2 thanks to a combined theoretical and experimental approach. Powder and thin film samples were characterized at synchrotron radiation light facilities to determine their local and long-range structure (EXAFS, XANES, HR-XRD) as well as their composition and electronic properties (XPS, RESPES). The observed experimental results are rationalized on the grounds of DFT calculations aimed at reproducing experimental geometries and electronic structure. In this way, a complete picture of the complex interplay between dopant addition and material properties is provided.