Preparation and Adsorption Photocatalytic Properties of PVA/TiO2 Colloidal Photonic Crystal Films.

Polyvinyl alcohol (PVA)/TiO₂/colloidal photonic crystal (CPC) films with photocatalytic properties are presented, where TiO₂ nanoparticles were introduced into the PVA gel network. Such PVA/TiO₂/CPC films possess three-dimensional periodic structures that are supported with a PVA/TiO₂ 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/TiO₂/CPC catalyst films showed better properties as the degradation of methylene blue (MB) by the PVA/TiO₂/CPC film catalyst in 4 h was 77~90%, while the degradation of MB by the PVA/TiO₂ 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.