Effects of F- doping on the photocatalytic activity and microstructures of nanocrystalline TiO2 powders
Effects of F- doping on the photocatalytic activity and microstructures of nanocrystalline TiO2 powders
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DOI：
10.1021/cm020027c
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发表时间：
2002-09-01
影响因子：
8.6
通讯作者：
Zhang, LZ
中科院分区：
文献类型：
--
作者：
Yu, JC;Yu, JG;Zhang, LZ
通过在混合的NH₄F - H₂O溶液中水解四异丙醇钛，开发了一种新颖且简单的制备具有锐钛矿相和板钛矿相的高光活性纳米晶F⁻掺杂TiO₂光催化剂的方法。通过差热分析 - 热重分析（DTA - TG）、X射线衍射（XRD）、X射线光电子能谱（XPS）、紫外 - 可见吸收光谱、光致发光光谱（PL）、透射电子显微镜（TEM）和BET比表面积对所制备的F⁻掺杂TiO₂粉末进行了表征。通过空气中丙酮的光催化氧化来评估光催化活性。结果表明，F⁻掺杂提高了锐钛矿的结晶度。此外，氟离子不仅抑制了板钛矿相的形成，还阻止了锐钛矿向金红石的相变。F⁻掺杂的TiO₂样品在紫外 - 可见范围内表现出更强的吸收，带隙跃迁发生红移。当NH₄F与H₂O的摩尔比保持在0.5 - 3的范围内时，通过这种方法制备的F⁻掺杂TiO₂粉末的光催化活性超过了德固赛P25。
A novel and simple method for preparing highly photoactive nanocrystalline F--doped TiO2 photocatalyst with anatase and brookite phase was developed by hydrolysis of titanium tetraisopropoxide in a mixed NH4F-H2O solution. The prepared F-doped TiO2 powders were characterized by differential thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis absorption spectroscopy, photoluminescence spectra (PL), transmission electron microscopy (TEM), and BET surface areas. The photocatalytic activity was evaluated by the photocatalytic oxidation of acetone in air. The results showed that the crystallinity of anatase was improved upon F- doping. Moreover, fluoride ions not only suppressed the formation of brookite phase but also prevented phase transition of anatase to rutile. The F-doped TiO2 samples exhibited stronger absorption in the UV-visible range with a red shift in the band gap transition. The photocatalytic activity of F-doped TiO2 powders prepared by this method exceeded that of Degussa P25 when the molar ratio of NH4F to H2O was kept in the range of 0.5-3.