Ex situ and in situ characterization studies of spin-coated TiO2 film electrodes for the electrochemical ozone production process
✍ Scribed by Kenta Kitsuka; Kazuhiro Kaneda; Mineo Ikematsu; Masahiro Iseki; Katsuhiko Mushiake; Takeo Ohsaka
- Publisher
- Elsevier Science
- Year
- 2009
- Tongue
- English
- Weight
- 859 KB
- Volume
- 55
- Category
- Article
- ISSN
- 0013-4686
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✦ Synopsis
An electrode composed of silicon/titanium oxide/platinum/titanium dioxide (Si/TiO X /Pt/TiO 2 ) was fabricated by spin-coating TiO 2 multilayers on a Si/TiO X /Pt substrate and was used in electrochemical ozone production (EOP). EOP was realized when the Si/TiO X /Pt substrate was completely covered with the TiO 2 film and a current efficiency of 7% was achieved at a low current density of 26.7 mA cm -2 in 0.01 M HClO 4 at 15 • C. The TiO 2 film was found to be of an anatase-type TiO 2 and that to comprise aperture structures from the X-ray diffraction (XRD) and transmission electron microscopy (TEM) observations. Moreover, the fabricated TiO 2 film was found to be an n-type semiconductor by photoelectrochemical measurements. The high efficiency at a low current density of EOP on the TiO 2 n-type semiconductor was explained to result from the electron transfer through the TiO 2 /HClO 4 interface as tunneling current. When the tunneling current passes through a depletion layer of TiO 2 , the electrode potential is necessarily high enough to facilitate EOP.