Pt 改性的高结晶度 TiO2 晶须的光催化性能

 以二钛酸钾 (K₂Ti₂O₅) 为前驱体, 通过离子交换和 800^oC 焙烧制备了 TiO₂晶须 (TiO₂(800^oC)), 并采用乙二醇胶体法, 在 TiO₂(800^oC) 样品上负载 1% Pt 纳米颗粒制成了 Pt/TiO₂(800^oC 催化剂. 采用 X 射线衍射、扫描电镜、透射电镜、X 荧光光谱和低温 N2 吸附-脱附等技术对催化剂进行了表征, 并考察了该催化剂光催化降解苯酚活性及稳定性. 结果表明, TiO₂(800^oC)样品为结晶度较高的纯锐钛矿 TiO₂, 载 Pt 后催化活性提高到原来的 2.3 倍, 具有很高的单位比表面积活性. 催化剂经 10 次重复使用后, Pt 流失量仅为 6%, 活性为新鲜催化剂的 91%. 而低结晶度的纯锐钛矿或混晶的 TiO₂ 负载 Pt 催化剂的活性和稳定性均不及 Pt/TiO₂(800^oC).

Highly Crystalline TiO2 Whisker Modified with Pt and Its Photocatalytic Performance

Highly thermally stable anatase TiO₂ whisker has been synthesized by ion-exchange and calcination at high temperature (800^oC) using K₂Ti₂O₅ as the precursor. Pt nanoparticles (1%) were loaded on this TiO₂ to prepare a Pt/TiO₂ catalyst by the glycol-colloidal method. The catalyst samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray fluo-rescence, and N₂ adsorption-desorption measurements. Photocatalytic performance of the Pt/TiO₂ catalyst was measured by phenol degrada-tion. The catalytic activity of Pt/TiO₂ was 2.3 times that of TiO₂ whisker, and the activity on per unit surface area was high. The Pt/TiO₂ cata-lyst was stable after reuse 10 times, and it maintained 91% of its initial activity because the loss of Pt was only 6%.