Porous SiO2/TiO2 Bilayer Antireflection Coatings with Self-cleaning Capacity

The porous SiO2/TiO2 bilayer antireflection coatings with self-cleaning capacity have been prepared by a sol-gel dip-coating method, the surfactant template, Pluronic F123 (PF123) was added to the sol as a pore generator. The performances of the coatings were analyzed with ultraviolet visible spectrophotometer (UV-Vis), scanning electron microscope (SEM) and atomic force microscopy (AFM). The self-cleaning function of coatings was evaluated by means of photocatalytic degradation of methyl orange in aqueous solution, and mechanical strength of the coatings has also been studied. The results indicate that the average transmittance of porous SiO2/TiO2 coating increases by 6% as compared to uncoated glass, the coating has a small particle size, a porous structure and a low roughness. After illuminated by ultraviolet light for 3 h, the 5 mg/L methyl orange can be degraded by 56.5%. In addition, the coating has an excellent mechanical strength.