TiO₂ doped with different atoms to modify its catalytic characteristics

TiO₂ has photocatalytic capabilities with a 2.9eV band gap. The gap is quite large and can only be used in very specific situations. By introducing different elements, the gap can be modified, it can introduce states in different positions of the gap, depending on the nature of the impurity. In this way, the photocatalytic characteristics of TiO₂ can be modified.
With electronic structure calculations based on Density Functional Theory the gap is underestimated. This can be solved by using the GW approximation, but this is quite computationally demanding. Recently Becke and Johnson proposed a potential to do these calculations, Tran and Blaha found a modification that reproduce the band gap with great accuracy and the computational cost is low, but the process is clumsy and it needs many iterations to converge. In this work, with the introduction of several cations in the TiO₂ lattice, we show some computational resources that can be employed in order to compute the new electronic structures, Ti_1-xA_xO₂, resulting from these doping processes.