Hostname: page-component-76fb5796d-zzh7m Total loading time: 0 Render date: 2024-04-28T01:46:25.193Z Has data issue: false hasContentIssue false
  • English
  • Français

Domain size change of spinodal phase separation structure in the sol-gel derived TiO2 thin film

Published online by Cambridge University Press:  01 January 2006

Ryohei Mori ,
Masahide Takahashi  and
Toshinobu Yoko
Ryohei Mori
Affiliation:
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
Masahide Takahashi*
Affiliation:
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
Toshinobu Yoko
Affiliation:
Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
*
a)Address all correspondence to this author. e-mail: ryohei@noncry.kuicr.kyoto-u.ac.jp
Get access

Abstract

TiO2 thin films were prepared with a spinodal phase separation structure ranging from hundreds of nanometers to micrometers in size by the sol-gel dip-coating method from a titanium tetraisopropoxide solution containing polyoxyethylene (20) nonylphenyl ether (NPE-20). It was possible to change the titania domain size of the spinodal phase separation structure by selecting alcohol as the solvent because the polycondensation and the phase separation are severely influenced by its evaporation rate from the surface of the coated film. It was also observed that the titania domains became larger in size as the film thickness increased in the bottom area of the substrate when the dip-coating method was applied, while uniformly sized titania domains were possibly formed by a spin-coating method. Furthermore, the contrast between the TiO2 phase and the air phase was not sharp when the titania domain size was smaller than several hundreds of nanometers. It was possible to prepare TiO2-air interconnective films with the spinodal phase separation structure 200–300 nm in domain size by subsequent HF etching. In addition, combining spinodal phase separation structure (SPSS) TiO2 thin film with different skeleton size has the potential to create TiO2 thin film with high photo-electron conversion efficiency due to its particular structure, higher surface area, and lack of bottleneck for electron transfer.

Keywords

CeramicFilmSol-gel
Type
Articles
Information
Journal of Materials Research , Volume 21 , Issue 1 , January 2006 , pp. 270 - 275
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1.Finklea, H.O.: Semiconductor Electrodes (Elsevier, Amsterdam, The Netherlands, 1988).Google Scholar
2.Hagfeldt, A. and Grätzel, M.: Light-induced redox reaction in nanocrystalline systems. Chem. Rev. 95, 49 (1995).CrossRefGoogle Scholar
3.O‘Regan, B. and Grätzel, M.: A low cost, high efficiency solar cell based on dye-sensitized colloidal TiO2 films. Nature (London) 353, 737 (1991).CrossRefGoogle Scholar
4.Bach, U., Lupo, D., Comte, P., Moser, J.E., Weissörtel, F., Salbeck, J., Spreitzer, H. and Grätzel, M.: Solid-state dye-sensitized mesoporous TiO2 solar cells with high proton-to-electron conversion efficiencies. Nature 395, 583 (1998).CrossRefGoogle Scholar
5.He, J., Lindström, H., Hagfeldt, A. and Lindquis, S.E.: Dye-sensitized nanostructured tandem cell first demonstrated cell with a dye-sensitized photocathode. Sol. Energy Mater. Sol. Cells 62, 265 (2000).CrossRefGoogle Scholar
6.Fujishima, A. and Honda, K.: Electrochemical photolysis of water at a semiconductor electrode. Nature 238, 37 (1972).CrossRefGoogle Scholar
7.Pichot, F., Suzanne, F., Pitts, and Gregg, R.J.: Flexible solid-state photoelectrochromic windows. J. Electrochem. Soc. 146, 4324 (1999).CrossRefGoogle Scholar
8.Yoshimura, K., Miki, T. and Tanemura, S.: TiO2 electrochromic thin films by reactive direct current magnetron sputtering. J. Vac. Sci. Technol. A 15, 2673 (1997).CrossRefGoogle Scholar
9.Ling, H., Keng, C. and Tung, C.Y.: Gas-sensing properties of nanocrystalline TiO2. Nanostruct. Mater. 9, 747 (1997).Google Scholar
10.Akbar, S.A. and Younkman, L.B.: Sensing mechanism of a carbon monoxide sensor based on anatase titania. J. Electrochem. Soc. 144, 1750 (1997).CrossRefGoogle Scholar
11.Mori, R., Takahashi, M. and Yoko, T.: 2D spinodal phase separated TiO2 films prepared by sol-gel process and photocatalytic activity. Mater. Res. Bull. 39, 2137 (2004).CrossRefGoogle Scholar
12.Nakanishi, K.: Pore structure control of silica gels based on phase separation. J. Porous Mater. 4, 67 (1997).CrossRefGoogle Scholar
13.de Jongh, P.E. and Vanmaekelbergh, D.: Investigation of the electronic transport properties of nanocrystalline particulate TiO2 electrodes by intensity-modulated photocurrent spectroscopy. J. Phys. Chem. B 101, 2716 (1997).CrossRefGoogle Scholar
14.Yang, C.C., Josefowicz, J.Y. and Alexandru, L.: Deposition of ultrathin films by a withdrawal method. Thin Solid Films 74, 117 (1980).CrossRefGoogle Scholar
15.Chan, J.W.: Phase separation by spinodal decomposition in isotropic systems. J. Chem. Phys. 42, 93 (1965).Google Scholar