AVS 54th International Symposium
    Advanced Surface Engineering Tuesday Sessions
       Session SE-TuP

Paper SE-TuP7
Effect of Internal Pressures for TiO2 based Colloidal Sols during Hydrothermal Process

Tuesday, October 16, 2007, 6:00 pm, Room 4C

Session: Advanced Surface Engineering Poster Session
Presenter: C.R. Yoon, Sejong University, Korea
Authors: C.R. Yoon, Sejong University, Korea
H.J. Oh, Sejong University, Korea
N.H. Lee, Sejong University, Korea
Y. Guo, Sejong University, Korea
S.J. Kim, Sejong University, Korea
Correspondent: Click to Email

Transparent TiO2 sols were prepared by hydrothermal synthesis to heat Ti precursor solutions, from Ti hydroxides obtained with neutralizing aqueous TiOCl2 solutions having various concentrations of NaCl by aqueous NaOH solution, in the autoclave at 120°C, and then their photocatalytic abilities using glass beads coated with the sol for gaseous benzene were evaluated. Because it was possible to prepare brookite phase TiO2 sol by external pressurization into the autoclave during the synthesis, the internal pressure in the autoclave was controlled using a technique with capturing Na ions in the lattice of Ti hydroxide. As a result, it was found that due to the increase of brookite phase in TiO2 by controlling the concentration of Na ion the optical absorption of TiO2 increases toward long wavelength but that in the range of short wavelength becomes relatively low and consequently the photocatalytic performance of TiO2 thin film for benzene gas rather decreases, compared to that of composite film of anatase and brookite phases. These results suggest that in order for coated TiO2 thin film to have high dissociation performance for benzene gas it is effective to form anatase and brookite phases compositely in TiO2.