Photoinduced Electron Transfer in a Chromophore–Catalyst Assembly Anchored to TiO 2
- Department of Chemistry, University of North Carolina at Chapel Hill, CB 3290, Chapel Hill, North Carolina 27599-3290, United States
Photoinduced formation, separation, and buildup of multiple redox equivalents are an integral part of cycles for producing solar fuels in dye-sensitized photoelectrosynthesis cells (DSPECs). Excitation wavelength-dependent electron injection, intra-assembly electron transfer, and pH-dependent back electron transfer on TiO2 were investigated for the molecular assembly [((PO3H2-CH2)-bpy)2Rua(bpy-NH-CO-trpy)Rub(bpy)(OH2)]4+ ([TiO2–RuaII–RubII–OH2]4+; ((PO3H2-CH2)2-bpy = ([2,2'-bipyridine]-4,4'-diylbis(methylene))diphosphonic acid); bpy-ph-NH-CO-trpy = 4-([2,2':6',2''-terpyridin]-4'-yl)-N-((4'-methyl-[2,2'-bipyridin]-4-yl)methyl) benzamide); bpy = 2,2'-bipyridine). This assembly combines a light-harvesting chromophore and a water oxidation catalyst linked by a synthetically flexible saturated bridge designed to enable long-lived charge-separated states. Following excitation of the chromophore, rapid electron injection into TiO2 and intra-assembly electron transfer occur on the subnanosecond time scale followed by microsecond–millisecond back electron transfer from the semiconductor to the oxidized catalyst, [TiO2(e–)–RuaII–RubIII–OH2]4+→[TiO2–RuaII–RubII–OH2]4+.
- Research Organization:
- Energy Frontier Research Centers (EFRC) (United States). Center for Solar Fuels (UNC EFRC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- SC0001011
- OSTI ID:
- 1387015
- Journal Information:
- Journal of the American Chemical Society, Vol. 134, Issue 46; Related Information: UNC partners with University of North Carolina (lead); Duke University; University of Florida; Georgia Institute of Technology; University; North Carolina Central University; Research Triangle Institute; ISSN 0002-7863
- Publisher:
- American Chemical Society (ACS)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
catalysis (homogeneous)
catalysis (heterogeneous)
solar (photovoltaic)
solar (fuels)
photosynthesis (natural and artificial)
hydrogen and fuel cells
electrodes - solar
charge transport
materials and chemistry by design
synthesis (novel materials)
synthesis (self-assembly)