Structural, electronic and optical DFT investigation of ruthenium doped anatase TiO 2 for photocatalytic applications

Structural, electronic and optical properties of Ru doped anatase TiO 2 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 TiO 2 exhibits good tetragonal structural stability. Beside the pure TiO 2 , we have studied the properties of the compositions RuTi 15 O 32 and RuTi 7 O 16 . We have noticed that TiO 2 semiconductor with a calculated band gap of 3.09 eV, when doped to RuTi 15 O 32 , 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 RuTi 7 O 16 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 TiO 2 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.