Ex situ and in situ characterization studies of spin-coated TiO(2) film electrodes for the electrochemical ozone production process

• Published in: Electrochimica acta Vol. 55; no. 1; pp. 31 - 36
• Main Authors: Kitsuka, Kenta, Kaneda, Kazuhiro, Ikematsu, Mineo, Iseki, Masahiro, Mushiake, Katsuhiko, Ohsaka, Takeo
• Format: Journal Article
• Language: English
• Published: 15.12.2009
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2009.07.059

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.