Preparation and Adsorption Photocatalytic Properties of PVA/TiO 2 Colloidal Photonic Crystal Films.

Polyvinyl alcohol (PVA)/TiO 2 /colloidal photonic crystal (CPC) films with photocatalytic properties are presented, where TiO 2 nanoparticles were introduced into the PVA gel network. Such PVA/TiO 2 /CPC films possess three-dimensional periodic structures that are supported with a PVA/TiO 2 composite gel. The unique structural color of CPCs can indicate the process of material preparation, adsorption, and desorption. The shift of diffraction peaks of CPCs can be more accurately determined using fiber-optic spectroscopy. The effect of the PVA/TiO 2 /CPC catalyst films showed better properties as the degradation of methylene blue (MB) by the PVA/TiO 2 /CPC film catalyst in 4 h was 77~90%, while the degradation of MB by the PVA/TiO 2 film was 33% in 4 h, indicating that the photonic crystal structure was 2.3~2.7 times more effective than that of the bulk structure.