Interestingly, the mesoporous TiO2/
SiO2 film prepared with the molar ratio of PVP/TTIP/TEOS
1.0:2.5 :2.5 (sample D) achieved a photodegradation rate that
was twice as fast as that of the mesoporous pure TiO2 film
(sample A), indicating that the addition of SiO2 is a very effective
way to increase the photocatalytic activity of TiO2 film