钛粉制备多级纳米结构TiO_2微球及其光催化特性

在NaOH溶液中采用水热法处理钛粉制备TiO2纳米针/带微球。利用场发射扫描电子显微镜（FESEM）、透射电子显微镜（TEM）、选区衍射（SAED）、紫外-可见吸收光谱（UV-vis）和X射线衍射仪（XRD）对样品结构进行表征。结果显示,水热温度和溶液浓度共同决定晶体的生长方向,纳米针/带微球的直径（40~50μm）与钛粉直径相当。纳米针/带微球经450°C热处理1h后转变锐钛矿。以甲基橙为目标考察样品的光催化活性。在相同条件下,样品的光催化活性为：TiO2纳米针微球〉TiO2纳米带微球〉P25。

Enhanced photocatalytic properties of hierarchical nanostructured TiO2 spheres synthesized with titanium powders

Using Ti powder as reagent, TiO 2 nanoneedle/nanoribbon spheres were prepared via hydrothermal method in NaOH solution. The samples were characterized by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) with selected area electron diffraction (SAED), X-ray diffraction (XRD), and UV-visible light absorption spectrum. The results indicate that the growth orientations of the crystals are influenced by the hydrothermal temperature and NaOH concentration. The diameter of the nanoneedle spheres and nanoribbon spheres (40 50 μm) are almost the same as that of Ti powders. TiO 2 nanoneedle/nanoribbon sphere powders are anatase after heat treatment at 450 °C for 1 h. Furthermore, methyl orange was used as a target molecule to estimate the photocatalytic activity of the specimens. Under the same testing conditions, the photocatalytic activities of the products decrease in the following order: TiO 2 nanoneedle sphere, TiO 2 nanoribbon sphere and P25.