Scientific Reports 5
Tuning the Electronic Structure of Anatase Through Fluorination
Dario Corradini, Damien Dambournet, Mathieu Salanne.
A highly fluorinated anatase lattice has been recently reported, providing a new class of materials whose general chemical formula is Ti1−x□xX4xO2−4x (X− = F− or OH−). To characterise the complex structural features of the material and the different F environments, we here apply a computational screening procedure. After deriving a polarisable force—field from DFT simulations, we screen in a step-wise fashion a large number of possible configurations differing in the positioning of the titanium vacancies (□) and of the fluorine atoms. At each step only 10% of the configurations are retained. At the end of the screening procedure, a configuration is selected and simulated using DFT-based molecular dynamics. This allows us to analyse the atomic structure of the material, which is strongly disordered, leading to a strong decrease (by 0.8 eV) of the band gap compared to conventional anatase.