Visible-Light-Active Titania Photocatalysts: The Case of N-Doped TiO₂s—Properties and Some Fundamental Issues

Figure 5

Electronic band structure for (a) substitutional and (b) interstitial N-doped anatase TiO₂ as given by PBE calculations at a low-symmetry 𝑘-point. In the former, the site contains the paramagnetic N²⁻ species making the site electrically neutral (replaced O²⁻), whereas in the latter the site is occupied by the radical NO. The estimated band gap energy is also indicated. Reproduced with permission from [48]. Copyright (2005) American Chemical Society.

(a)

(b)