水热法制备三维网状TiO2纳米线薄膜及其光电化学性能

为了构建纳米二氧化钛(TiO2)的特殊结构以提高TiO2纳米材料的光催化性能, 利用水热法在钛箔表面制备了三维网络结构的TiO2纳米线薄膜(W-film). 通过场发射扫描电子显微镜(FESEM)及X射线衍射(XRD)仪对样品进行了表征. 结果表明, 三维网络TiO2纳米线薄膜是由大量非定向生长的锐钛矿型纳米线组成, 直径为10-30 nm, 长度大于5 μm. 利用紫外-可见分光光度计(UV-Vis)对W-film 进行光学性能研究, 结果表明在350-700 nm波长范围内W-film的吸光度均大于TiO2纳米粒子(P25)薄膜(P-film)的吸收度, 同时吸收带边发生红移, 且吸光度随水热时间增加而增加. 进一步在Na2SO4溶液中研究了W-film的光电化学性能, 结果表明其光电化学性能较P-film优异. 并以甲基橙为目标降解物考察了W-film的光催化性能. 在相同测试条件下, W-film光催化降解甲基橙的速率是P-film的2.3倍, 展示了良好的应用前景. 这种复合W-film电极兼有柔性和可外加电场的双重优点, 拓展了TiO2薄膜的应用领域.

Photoelectrochemical Properties of Three-Dimensional Network TiO2 Nanowire Film Prepared by Hydrothermal Method

The construction of TiO2with a special architecture to enhance the photocatalytic property of nano-titanium dioxide (TiO2) was achieved by synthesizing a three-dimensional (3D) network TiO2 nanowire film (W-film) on the surface of Ti foil using a hydrothermal method. Samples were characterized by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Results showed that the three-dimensional network nanowire film was composed of many randomly-oriented anatase nanowires, which had diameters of 10-30 nmand lengths larger than 5 μm. Optical properties of these W-films were studied by UV-Vis spectrophotometry (UV-Vis). The results indicated that the absorbency of the W-film was higher than that of a particulate film (P-film) in the 350-700 nm region and the absorption edge was red-shifted. Meanwhile, the absorbency of the W-film increased as the hydrothermal time increased. After further investigation of the photoelectrochemical properties of the W-film in Na2SO4 solution, we determined that the photoelectrochemical properties of the W-film were better than those of P-film. Methyl orange was used as a target molecule to estimate the photocatalytic activity of the W-film. Under the same testing conditions, the catalytic efficiency of the W-film was found to be 2.3 times as that of the P-film and it, therefore, has a bright future. This kind of composited W-film electrode possesses advantages both in flexibility and implementation of the applied potential, which will increase the application field of this TiO2 film.