Preparation and crystallization characteristics of mesoporous TiO2 and mixed oxides

Junko N. Kondo; Tomohiro Yamashita; Kiyotaka Nakajima; Daling Lu; Michikazu Hara; Kazunari Domen

doi:10.1039/B418331B

Preparation and crystallization characteristics of mesoporous TiO₂ and mixed oxides†

Junko N. Kondo,*^a Tomohiro Yamashita,^a Kiyotaka Nakajima,^a Daling Lu,^a Michikazu Hara^a and Kazunari Domen^bc

* Corresponding authors

^a Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama, Japan
E-mail: jnomura@res.titech.ac.jp
Fax: +81-45-924-5282
Tel: +81-45-924-5238

^b Department of Chemical System Engineering, School of Engineering, The University of Tokyo7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan

^c Research Office of Solution-Oriented Research for Science and Technology (SORST), Japan Science and Technology Corporation, Nihonbashi 3-4-15, Yaesudori Bldg. 9F, Chuo-ku, Tokyo, Japan

Abstract

Mesoporous TiO₂ and mixed Ti oxides are prepared by a modified sol-gel method using a block copolymer as a mesoporous template. Calcination of the material at 400 °C for template removal is shown to induce crystallization of pure TiO₂, resulting in the destruction of the original mesoporous structure and the development of larger pores (7.5 nm) as inter-particle voids. The addition of tri-, tetra- and penta-valent metals (Al, Zr and Nb) to Ti oxide in the amorphous phase in the ratio Ti : M = 1 : 2 (M = Al, Zr or Nb) increases the thermal stability of the material by elevating the crystallization temperature above that for pure TiO₂. The formation of Al₂TiO₅, TiZr₂O₆ and TiNb₂O₇ crystal phases without phase separation is confirmed in these materials, demonstrating the homogeneous mixing of TiO₂ and the additive element at the atomic level. The mixed mesoporous oxides are thermally stable at 400 °C, although the porous structure is still destroyed due to crystallization. Thus, a homogeneous mixture of Ti with another element (Al, Zr or Nb) in mesoporous amorphous Ti-mixed oxide is observed.

Supplementary files

Article information

DOI: https://doi.org/10.1039/B418331B
Article type: Paper
Submitted: 06 Dec 2004
Accepted: 24 Mar 2005
First published: 18 Apr 2005

Download Citation

J. Mater. Chem., 2005,15, 2035-2040

Permissions

Request permissions

Preparation and crystallization characteristics of mesoporous TiO₂ and mixed oxides

J. N. Kondo, T. Yamashita, K. Nakajima, D. Lu, M. Hara and K. Domen, J. Mater. Chem., 2005, 15, 2035 DOI: 10.1039/B418331B

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Journal of Materials Chemistry