物理化学学报 >> 2009, Vol. 25 >> Issue (05): 1013-1018.doi: 10.3866/PKU.WHXB20090421

研究论文 上一篇    下一篇

介孔TiO2的水热法制备及其光催化性能

沈晶晶 刘畅 朱育丹 李伟 冯新 陆小华   

  1. 南京工业大学材料化学工程国家重点实验室, 南京210009
  • 收稿日期:2008-11-24 修回日期:2009-01-06 发布日期:2009-05-04
  • 通讯作者: 陆小华 E-mail:xhlu@njut.edu.cn

Photocatalytic Properties of Mesoporous TiO2 Prepared by Hydrothermal Method

SHEN Jing-Jing, LIU Chang, ZHU Yu-Dan, LI Wei, FENG Xin, LU Xiao-Hua   

  1. State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Nanjing 210009, P. R. China
  • Received:2008-11-24 Revised:2009-01-06 Published:2009-05-04
  • Contact: LU Xiao-Hua E-mail:xhlu@njut.edu.cn

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摘要：

以二钛酸钾(K2Ti2O5)经离子交换得到的无定形水合二钛酸(H2Ti2O5·xH2O)为原料, 与葡萄糖溶液在220 ℃下进行水热反应, 再在空气中520 ℃焙烧, 制备出介孔TiO2. 用扫描电子显微镜(SEM)、X射线衍射(XRD)、N2吸附、透射电子显微镜(TEM)等技术对样品进行了表征. 结果表明, 该介孔TiO2具有微米级棒状或针状形貌, 晶粒大小为12.3 nm, 比表面积为106 m2·g-1, 孔容为0.31 cm3·g-1, 孔径为8.06 nm, 焙烧处理后晶型仍是锐钛矿相. 水热生成的碳抑制了晶粒的团聚生长和晶型的转变, 提高了介孔TiO2的热稳定性. 甲基橙降解实验评价了介孔TiO2的光催化性能, 结果发现其活性与商用TiO2催化剂P25相当, 而其较大的粒径更容易回收再利用. 以碘化钾为探针反应, 表明介孔TiO2的光催化机制以光生空穴氧化为主.

关键词: 介孔TiO2, 水热碳化, 空穴氧化, 光催化

Abstract:

Mesoporous TiO2 was synthesized by hydrothermal treatment of titanic acid hydrate (H2Ti2O5·xH2O) from potassium titanate (K2Ti2O5) via ion-exchange and glucose in aqueous solution at 220 ℃, followed by a posttreatment in the presence of air at 520 ℃. The photocatalyst was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), N2 adsorption, and transmission electron microscopy (TEM). Results indicated that the prepared mesoporous TiO2 photocatalyst was micron-sized rod or needle morphology and had a mesoporous structure with a surface area of 106 m2·g-1, pore volume of 0.31 cm3·g-1, and a pore diameter of 8.06 nm. The crystal size was 12.3 nm. After calcination it was still anatase phase. The produced carbon considerably increased the thermal stability of the mesoporous TiO2 framework and inhibited undesirable grain growth as well as phase transformation during the hydrothermal and thermal treatment process. Photocatalytic degradation performance was investigated using methyl orange pollutant. The mesoporous TiO2 photocatalyst and Degussa P25 showed similar degradation behavior toward methyl orange. The mesoporous TiO2 could be recycled many times and this was because of the large grain size. Using KI as a probe reaction, we found that the photocatalytic mechanism of mesoporous TiO2 depended on photoinduced hole oxidation.

Key words: Mesoporous TiO2, Hydrothermal carbonization, Hole oxidation, Photocatalysis