关键词: 多孔TiO2薄膜, 表面形态修饰, 亲水性, 硝酸铵, 溶胶-凝胶

Abstract: Pore modified TiO2 thin films were prepared by adding ammonium nitrate into TiO2 sol precursor and using dip-coating technique. The formation process of pores in TiO2 thin film is closely related to the phase separation induced by ammonium nitrate in dip-coated TiO2 sol film. Ammonium nitrate in the dip-coated TiO2 sol film not only suppresses the evaporation of condensed water during the drying process but also increases the surface tension of water phase，which enhances the formation of water droplets which remains pores in the dried gel after being completely evaporated. The formed TiO2 thin films showed excellent superhydrophilicity. The pore distribution density increased and the transmittance of visible light deceased as the amount of ammonium nitrate was increased. Increase of repeating times of the coating process produced a multilayer pore modified film surface which was favorable to increase the transmittance of visible light.

Key words: porous TiO2 film, surface modification, hydrophilicity, ammonium nitrate, sol-gel