Dye-sensitizing effect of TiOPc thin film on n-TiO2 (001) surface

Hisao Yanagi, Siying Chen, Paul A. Lee, Ken W. Nebesny, Neal R Armstrong, Akira Fujishima

Research output: Contribution to journalArticle

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Abstract

Dye-sensitization processes for the (001) surface of n-type titanium oxide (n-TiO2) single crystal coated with vacuum-deposited titanylphthalocyanine (TiOPc) were investigated by means of photoelectrochemical measurements and X-ray and ultraviolet photoelectron spectroscopy (XPS, UPS). The electrode of n-TiO2 coated with TiOPc exhibited two photooxidation current bands in an aqueous electrolyte including hydroquinone (H2Q), due to direct excitation of n-TiO2 below 420 nm and electron transfer from TiOPc to n-TiO2 under the Q-band absorption of TiOPc at 600-800 nm, respectively. The former photocurrent process due to n-TiO2 excitation was remarkably decreased by presence of surface states, which originated from defects of oxygen induced by Ar ion bombardment of the n-TiO2 surface. The photooxidation process sensitized by the latter was evaluated from the determined energy levels of electronic bands for n-TiO2 and TiOPc. The LUMO level of TiOPc was located 0.3 eV above that of n-TiO2, which enabled electrons to transfer from TiOPc to n-TiO2. The excited state of TiOPc was not quenched by the surface states of n-TiO2 but was efficiently transferred to n-TiO2 at the n-TiO2/TiOPc interface.

Original languageEnglish (US)
Pages (from-to)5447-5451
Number of pages5
JournalJournal of Physical Chemistry
Volume100
Issue number13
StatePublished - Mar 28 1996

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sensitizing
Photooxidation
Surface states
Coloring Agents
X ray photoelectron spectroscopy
Dyes
dyes
Ultraviolet photoelectron spectroscopy
Thin films
Electrons
photooxidation
Titanium oxides
thin films
Ion bombardment
Photocurrents
Excited states
Electron energy levels
Electrolytes
Absorption spectra
Single crystals

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Yanagi, H., Chen, S., Lee, P. A., Nebesny, K. W., Armstrong, N. R., & Fujishima, A. (1996). Dye-sensitizing effect of TiOPc thin film on n-TiO2 (001) surface. Journal of Physical Chemistry, 100(13), 5447-5451.

Dye-sensitizing effect of TiOPc thin film on n-TiO2 (001) surface. / Yanagi, Hisao; Chen, Siying; Lee, Paul A.; Nebesny, Ken W.; Armstrong, Neal R; Fujishima, Akira.

In: Journal of Physical Chemistry, Vol. 100, No. 13, 28.03.1996, p. 5447-5451.

Research output: Contribution to journalArticle

Yanagi, H, Chen, S, Lee, PA, Nebesny, KW, Armstrong, NR & Fujishima, A 1996, 'Dye-sensitizing effect of TiOPc thin film on n-TiO2 (001) surface', Journal of Physical Chemistry, vol. 100, no. 13, pp. 5447-5451.
Yanagi H, Chen S, Lee PA, Nebesny KW, Armstrong NR, Fujishima A. Dye-sensitizing effect of TiOPc thin film on n-TiO2 (001) surface. Journal of Physical Chemistry. 1996 Mar 28;100(13):5447-5451.
Yanagi, Hisao ; Chen, Siying ; Lee, Paul A. ; Nebesny, Ken W. ; Armstrong, Neal R ; Fujishima, Akira. / Dye-sensitizing effect of TiOPc thin film on n-TiO2 (001) surface. In: Journal of Physical Chemistry. 1996 ; Vol. 100, No. 13. pp. 5447-5451.
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