TY - GEN
T1 - Anchoring group and auxilary ligand effects on the binding of ruthenium complexes to nanocrystalline TiO2 photoelectrodes
AU - Kilså, Kristine
AU - Mayo, Elizabeth I.
AU - Katz, Jordan
AU - Brunschwig, Bruce S.
AU - Gray, Harry B.
AU - Lewis, Nathan S.
AU - Winkler, Jay R.
PY - 2006/10/16
Y1 - 2006/10/16
N2 - The thermodynamics and kinetics of binding to nanocrystalline TiO 2 were investigated for four ruthenium complexes with different numbers of possible anchoring groups and auxiliary ligands. Infrared spectroscopic data indicated that the dyes bound in a bridging mode with the oxygen atoms bound to separate titanium atoms. Complexes with only one or two anchoring groups used all of their carboxy groups to bind. Complexes having four or six linkers, used two groups in binding. The dyes yielded similar maximum coverages on TiO2, but different binding constants and desorption kinetics. The binding constant for the monocarboxy dye was lower than for the others. The adsorption rate constants were all similar, suggesting that formation of the first bond to TiO2 was rate limiting. Binding of the dyes from a buffered ethanol solution yielded lower coverages than from neat ethanol, although binding constants increased up to 100 times, indicating competition for, and/or deactivation of, TiO2 sites. For the monocarboxy dye, the integrated quantum yield was lowest, and electron transfer between TiO2 and the redox couple was most facile.
AB - The thermodynamics and kinetics of binding to nanocrystalline TiO 2 were investigated for four ruthenium complexes with different numbers of possible anchoring groups and auxiliary ligands. Infrared spectroscopic data indicated that the dyes bound in a bridging mode with the oxygen atoms bound to separate titanium atoms. Complexes with only one or two anchoring groups used all of their carboxy groups to bind. Complexes having four or six linkers, used two groups in binding. The dyes yielded similar maximum coverages on TiO2, but different binding constants and desorption kinetics. The binding constant for the monocarboxy dye was lower than for the others. The adsorption rate constants were all similar, suggesting that formation of the first bond to TiO2 was rate limiting. Binding of the dyes from a buffered ethanol solution yielded lower coverages than from neat ethanol, although binding constants increased up to 100 times, indicating competition for, and/or deactivation of, TiO2 sites. For the monocarboxy dye, the integrated quantum yield was lowest, and electron transfer between TiO2 and the redox couple was most facile.
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M3 - Conference contribution
AN - SCOPUS:33749564030
SN - 1566774357
SN - 9781566774352
T3 - Proceedings - Electrochemical Society
SP - 49
EP - 63
BT - Electron Transfer in Nanomaterials - Proceedings of the International Symposium
T2 - 205th Electrochemical Society Meeting
Y2 - 9 May 2004 through 14 May 2004
ER -