Figure 1

Possible positions of non-metals X (=N, C, S, Se) dopants in anatase TiO2 viz. (X)O, (XO)O and (X2)O (see text for details).
Possible positions of non-metals X (=N, C, S, Se) dopants in anatase TiO2 viz. (X)O, (XO)O and (X2)O (see text for details).