Study of Excited States and Electron Transfer of Semiconductor‐Metal‐Complex Hybrid Photocatalysts for CO 2 Reduction by Using Picosecond Time‐Resolved Spectroscopies
| Autor: | Tomiko M. Suzuki, Shunsuke Sato, Takeshi Morikawa, Ken Onda, Shu Saeki, Keita Sekizawa, Ken ichi Yamanaka, Sei'ichi Tanaka |
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| Rok vydání: | 2020 |
| Předmět: |
010405 organic chemistry
business.industry Chemistry Organic Chemistry Infrared spectroscopy General Chemistry 010402 general chemistry Photochemistry 01 natural sciences Catalysis 0104 chemical sciences Photoexcitation Electron transfer Semiconductor Picosecond Excited state Photocatalysis business |
| Zdroj: | Chemistry – A European Journal. 27:1127-1137 |
| ISSN: | 1521-3765 0947-6539 |
| DOI: | 10.1002/chem.202004068 |
| Popis: | A semiconductor-metal-complex hybrid photocatalyst was previously reported for CO2 reduction; this photocatalyst is composed of nitrogen-doped Ta2 O5 as a semiconductor photosensitizer and a Ru complex as a CO2 reduction catalyst, operating under visible light (>400 nm), with high selectivity for HCOOH formation of more than 75 %. The electron transfer from a photoactive semiconductor to the metal-complex catalyst is a key process for photocatalytic CO2 reduction with hybrid photocatalysts. Herein, the excited-state dynamics of several hybrid photocatalysts are described by using time-resolved emission and infrared absorption spectroscopies to understand the mechanism of electron transfer from a semiconductor to the metal-complex catalyst. The results show that electron transfer from the semiconductor to the metal-complex catalyst does not occur directly upon photoexcitation, but that the photoexcited electron transfers to a new excited state. On the basis of the present results and previous reports, it is suggested that the excited state is a charge-transfer state located between shallow defects of the semiconductor and the metal-complex catalyst. |
| Databáze: | OpenAIRE |
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