Nanotechnological Advances in Catalytic Thin Films for Green Large-Area Surfaces

Figure 4

Suggested schemes for visible-light absorption in doped anatase TiO₂ by nonmetal doping: (a) narrowing of bandgap; (b) introduction of localized states above valence band; (c) introduction of localized states below conduction band; (d) formation of color centres in the bandgap; and (e) sensitization by compounds containing nitrogen species, reproduced from [76] with permission from The Royal Society of Chemistry.

(a)

(b)

(c)

(d)

(e)