Band-Gap Engineering for Photocatalytic Applications: Anionic and Cationic Doping of TiO2 Anatase

Structural and electronic properties of TiO2, S and Mo doped TiO2 anatase were investigated by means of Density Functional Theory with the B3LYP hybrid functional. Calculated structural and electronic properties of TiO2 show good agreement with experimental and theoretical predictions. Structural property reveals that the unit cell volume for doped TiO2 is controlled by the ionic radius of the dopant. Density of States and Band Structure results indicate the band-gap narrowing from creation of midgap states instead of band-gap widening resulting in an enhancement of photocatalytic behavior in comparison to TiO2.