镶嵌Pt的二氧化钛纳米管的合成及其光催化性能研究

以金红石相二氧化钛(TiO2)粉体为原料,采用水热法合成了二氧化钛纳米管(Titania nanotubes,简写为TNTs),然后把H2PtCl6的无水乙醇溶液引入到TNTs中,得到镶嵌Pt的二氧化钛纳米管(Pt/TNTs).利用透射电镜(TEM)、X射线衍射(XRI))和紫外-可见光谱(UV-Vis)对产物进行了表征,并重点研究了Pt/TNTs的光催化性能.结果表明,有直径约为3 nm的Pt纳米粒子插入到了TNTs中,且Pt粒子以Pt单质的形式存在.Pt/TNTs在可见光区域表现出较强的吸收,并且其起始吸收带边发牛明显红移.紫外光催化降解甲基橙实验结果表明,金红石相TiO2,TNTs和Pt/TNTs对甲基橙溶液的降解率分别达到46.8%,57.2%和84.6%,Pt/TNTs的光催化活性较金红石相二氧化钛粉体和纯TNTs有显著的提高.

Fabrication and Photocatalytic Activity of Pt-Inserted Titania Nanotubes

Titania nanotubes (TNTs) were synthesized by hydrothermal treatment of rutile-phase TiO2 nanoparticals in NaOH solution at 110 ℃ for 24 hours. After drying in aceton for 36 h, the TNTs were under vacuum drying for 24 h at room temperature. The Pt-inserted titania nanotubes (Pt/TNTs) were obtained by filling H2PtCl6 ethanol solution into the TNTs after vacuum drying. The characterizations of the as-synthesized samples were confirmed by TEM, XRD, and UV-Vis. The photocatalytic activity of the Pt/TNTs was investigated by photo-induced decomposition of methyl orange(MO)under the main 365 nm UV-light. In order to comparison, the photocatalytic activity of both the rutile-phase TiO2 nanoparticles and pure TNTs were also investigated at the same time under the same experimental conditions. The TEM images show that the TNTs are hollow, a few hundred nanometers long, and the inner/outer diameter is about 6/10 nm. The crystal structure of TNTs is H2Ti2O5·H2O with a little Na. Both the shape and the crystalline of the TNTs are not changed after the modification. The oval or round Pt0 nanoparticals, about 3 nm in diameter, are found only in the nanotubes. Pt/TNTs exhibit enhanced absorption at the visible range in the UV-Vis spectra and its start absorption band edge(λ0≈457 nm)is obviously redshifted compared to the rutile-phase TiO2 nanoparticals and pure TNTs. The Pt nanoparticles are found to significantly enhance the photocatalytic activity of TNTs. Pt/TNTs are demonstrated to be highly efficient for the UV-light induced photocatalytic decomposition of MO compared to both the rutile-phase TiO2 nanoparticals and pure TNTs. After irradiation for 60 min, the photocatalysis decomposition rate of MO in rutile-phase TiO2 nanoparticals, TNTs and Pt/TNTs are 46.8%, 57.2% and 84.6% respectively.