Structural, electronic and optical DFT investigation of ruthenium doped anatase TiO2 for photocatalytic applications

Structural, electronic and optical properties of Ru doped anatase TiO2 have been carried out by density functional theory (DFT) calculation method in order to investigate the effect of ruthenium doping fraction and explore new properties of the material. The doped TiO2 exhibits good tetragonal structural stability. Beside the pure TiO2, we have studied the properties of the compositions RuTi15O32 and RuTi7O16. We have noticed that TiO2 semiconductor with a calculated band gap of 3.09 eV, when doped to RuTi15O32, exhibits a remarkable decrease of the bandgap width resulting from spin-up and spin-down states. Moreover, when increasing the Ru fraction no bandgap has been observed. In fact, the RuTi7O16 material has shown a metallic behavior. In addition, the dielectric function and the absorption coefficient have been discussed for the different doped systems. The results obtained herein suggest that the incorporation of ruthenium in TiO2 crystal structure may form new materials with novel properties suitable for possible use in prospective technologies such as photocatalytic applications, as well as in spintronic and optoelectronic devices.