糖葫芦状二氧化钛纳米线阵列的制备及其光催化性能

 采用溶胶-电泳技术,在多孔阳极氧化铝(PAA)模板的有序孔洞中制备了高度取向的糖葫芦状TiO2纳米线阵列光催化剂,通过扫描电镜(SEM)和X射线衍射对样品进行了表征. 结果表明, TiO2纳米线为锐钛矿晶型,纳米线直径与PAA模板的孔径一致,且分布均匀. 纳米线取向性极好,每根纳米线都具有周期性凹凸,形似糖葫芦,因此命名为糖葫芦状TiO2纳米线阵列. 以甲基橙的降解反应评价了光催化剂的活性,与相同条件下制备的TiO2/玻璃膜相比, TiO2纳米线阵列在光照1 h时对甲基橙的降解率达到93.6%, 比前者提高了40.2%, 具有很好的光催化活性.

Preparation and Photocatalytic Properties of Titania Nanowire Arrays with Shape of String of Candied Haws

The titania nanowire arrays with good orientation and a shape of strings of candied haws were prepared using a highly ordered porous anodic alumina(PAA) template by the sol-electrophoresis method.X-ray diffraction and scanning electron microscopy were applied to characterize the titania nanowire arrays.The crystalline phase of the titania nanowires is anatase.The diameter of the nanowires is uniformly distributed and is consistent with the pore size of PAA.The periodic concave-convex structure was found in each nanowire.The photocatalytic activity of the titania nanowires was measured by degradation of a methyl orange solution.Compared with the TiO_2 film on glass,the titania nanowire arrays have higher photocatalytic activity.Under the condition of 1 h irradiation,the degradation ratio of methyl orange increases to 93.6%,much higher than that of TiO_2 film on glass(53.4%).Using this method,the self-immobilization of the titania photocatalyst can be easily achieved.In addition,the mechanism of the high photocatalytic activity is discussed.