Dye-Sensitizing Effect of TiOPc Thin Film on n-TiO2 (001) Surface
| Autor: | Paul A. Lee, Ken W. Nebesny, Hisao Yanagi, Neal R. Armstrong, Akira Fujishima, S.-Y. Chen |
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| Rok vydání: | 1996 |
| Předmět: | |
| Zdroj: | The Journal of Physical Chemistry. 100:5447-5451 |
| ISSN: | 1541-5740 0022-3654 |
| Popis: | 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 electron... |
| Databáze: | OpenAIRE |
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