硅球多层模板溶胶浸渍法制备有序多孔TiO_2薄膜(英文)

Ordered Porous TiO_2 Films Assembled by Sol-dipping Method with Multilayer Silica Spheres Template

采用垂直沉积法组装了平均球径为188nm的三维有序二氧化硅微球阵列。以该阵列为模板,通过在TiO_2前驱体溶胶中多次浸渍热处理循环,随后采用超声辅助的NaOH溶液腐蚀去除硅球模板,制备了>20层厚的反转结构的二氧化钛多孔膜。该二氧化钛薄膜在550℃下热处理20h其多孔结构保持不变,表明采用此方法制备的二氧化钛多孔膜具有较好的热稳定性。X射线衍射图表明550℃下热处理得到的是具有锐钛矿结构的二氧化钛多孔膜。透光光谱显示了光子带隙出现在￣400nm。通过SEM观察,二氧化钛多孔膜的平均孔径为180nm(±3),收缩率约为4.3%,与布拉格衍射方程计算的结果176nm有较好的吻合。

Three-dimensionally ordered porous TiO2 films were prepared by sol-dipping method using silica spheres multilayer templates. The templates were previously assembled on glass substrates by vertical deposition method from purified silica spheres alcosol. Ultrasonic-assisted NaOH etching was employed in the removal of silica spheres templates. The inverted TiO2 film was heat-treated at 550 ℃ for 20 h and the porous structure remained unchanged implying a good thermal stability. X-ray diffraction （XRD） results indicate that the inverted TiO2 film is with anatase structure. ESEM images show that the average center-to-center distance between pores of the TiO2 film is 180 nm （±3）, about 4.3% smaller than that of the original silica sphere, which is consistent with the value of 176 nm calculated according to the Bragg law. The transmission spectrum shows an attenuation band around wavelength of 400 nm.