Electronic structure of N doped TiO$_{2}$: Hard x-ray photoemission study

We have determined the electronic structure of N doped TiO$_{2}$ using a combination of synchrotron based hard x-ray photoemission spectroscopy (HAXPES) and first principle density functional theory calculations. Comparison with calculations and experiment reveals strong evidence of hybridization between different orbital components. Our results reveal that N doping of TiO$_2$ leads to the formation of oxygen vacancies and the combination of both N impurity and oxygen vacancies accounts for the observed visible light catalytic behavior of Ndoped TiO$_2$.