Abstract: TiO2 ordered porous films (TIO) were fabricated via TiCl4 sol-gel dip-coating process using self-assembly SiO2 colloidal crystal as templates and Ag nanoparticles were achieved on the TIO by a liquid infiltration route, and Ag/TiO2 ordered porous composite films (ATIO) were obtained. The characteristics of the composite films were measured by Raman, FESEM, TEM, XPS and UV-vis. The results reveal that the average size of Ag nanoparticles is about 10 nm, and strong interaction exists between Ag nanoparticles and TiO2 nanocrystals. Visible light photocatalytic activities of samples with different Ag/Ti relative atomic concentration ratios and cycling tests were evaluated by analyzing the degradation of methylene blue (MB) in aqueous solution, and were compared with Ag/TiO2 disordered composite films (ATF). It is found that the TIO with AgNO3 concentration value 10 mmol/L in the precursor solution exhibits 319 times visible light degradation rate compared with conventional Ag deposited TiO2 disordered film without the ordered porous structure. This obvious enhanced visible-light photocatalytic activity for the Ag deposited TIO sample can be attributed to the synergetic effect of Ag nanoparticles and TIO ordered porous structures. The repeated cycling tests suggest that samples show stable photocatalytic activity.

Key words: TiO2 ordered porous film, Ag nanoparticle, synergetic effect, photocatalytic activity