| TiO2 films | Sol | Ti(O-i-Pr)4 (mol/dm3) | Urea (mol/dm3) | H2O (mol/dm3) | UV irradiation |
| (A) | (a) | 0.25 | 0.5 | 0.5 | Irradiated |
| (B) | (b) | 0.25 | 0 | 0.5 | Irradiated |
| (C) | (c) | 0.25 | 0.5 | 0.5 | Non |
| (D) | (d) | 0.25 | 0 | 0.5 | Non |