Evidence that ΔS‡ Controls Interfacial Electron Transfer Dynamics from Anatase TiO2 to Molecular Acceptors
| Autor: | Gerald J. Meyer, Seth L. Marquard, Brian N. DiMarco, Renato N. Sampaio, Ludovic Troian-Gautier |
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| Rok vydání: | 2018 |
| Předmět: |
Arrhenius equation
Anatase Chemistry Kinetics chemistry.chemical_element 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry Triphenylamine 01 natural sciences Biochemistry Catalysis 0104 chemical sciences Ruthenium symbols.namesake chemistry.chemical_compound Electron transfer Colloid and Surface Chemistry Covalent bond symbols 0210 nano-technology Acetonitrile |
| Zdroj: | Journal of the American Chemical Society. 140:3019-3029 |
| ISSN: | 1520-5126 0002-7863 |
| DOI: | 10.1021/jacs.7b13243 |
| Popis: | Recombination of electrons injected into TiO2 with molecular acceptors present at the interface represents an important loss mechanism in dye-sensitized water oxidation and electrical power generation. Herein, the kinetics for this interfacial electron transfer reaction to oxidized triphenylamine (TPA) acceptors was quantified over a 70° temperature range for para-methyl-TPA (Me-TPA) dissolved in acetonitrile solution, 4-[N,N-di(p-tolyl)amino]benzylphosphonic acid (a-TPA) anchored to the TiO2, and a TPA covalently bound to a ruthenium sensitizer, [Ru(tpy-C6H4-PO3H2)(tpy-TPA)]2+ “RuTPA”, where tpy is 2,2′:6′,2′′-terpyridine. Activation energies extracted from an Arrhenius analysis were found to be 11 ± 1 kJ mol–1 for Me-TPA and 22 ± 1 kJ mol–1 for a-TPA, values that were insensitive to the identity of different sensitizers. Recombination to RuTPA+ proceeded with Ea = 27 ± 1 kJ mol–1 that decreased to 19 ± 1 kJ mol–1 when recombination occurred to an oxidized para-methoxy TPA (MeO-TPA) dissolved in CH3CN. E... |
| Databáze: | OpenAIRE |
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