Dye Sensitization of Nanocrystalline Titanium Dioxide with Osmium and Ruthenium Polypyridyl Complexes
Abstract
A series of osmium polypyridyl complexes having various ground-state reduction potentials has been synthesized and used to sensitize nanoporous titanium dioxide electrodes to solar illumination. The spectral response and current vs potential properties of electrodes modified with these dyes have been compared with the behavior of their ruthenium analogues. The trends can be explained by the differences in absorption spectra and ground-state redox potentials. The osmium complexes appear to be promising candidates for further optimization in operating photoelectrochemical cells for solar energy conversion applications. Of the materials studied, all complexes having ground-state redox potentials in methanol more positive than ∼0.4 V vs aqueous SCE were able to sustain oxidation of I-/I_3- with a high steady-state quantum yield. For electrodes with very low dye coverages, the open-circuit voltage was mainly determined by the rate of reduction of I_2, whereas for high dye coverages, the open-circuit voltage depended on the nature of the complex and on the dye loading level.
Additional Information
© 2000 American Chemical Society. Received: January 14, 2000; In Final Form: April 6, 2000. Publication Date (Web): June 30, 2000. Support for this project was provided by the U.S. Department of Energy, DE-FG07-96ER14725. M. Cass thanks Prof. John Burmeister of the University of Maryland for useful discussions on linkage isomerism in metal thiocyanate and metal isothiocyanate complexes, and Profs. H. Gray and J. Bercaw of Caltech are acknowledged for numerous helpful discussions. We are grateful to Dr. Andy Maverick at Louisiana State University for measuring the emission spectra of Os(H_2L')_2(NCS)_2. Geneviève Sauvé thanks FCAR (Fonds pour la Formation de Chercheurs et l'Aide à la Recherche, Québec, Canada) for a scholarship, and S.D. acknowledges the U.S. Global Change Fellowship Program for a postdoctoral fellowship. We also thank Kodak for a generous gift in support of studies of photoelectrochemistry at Caltech.Attached Files
Supplemental Material - jp0002143_s.pdf
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Additional details
- Eprint ID
- 75693
- Resolver ID
- CaltechAUTHORS:20170404-105006672
- Department of Energy (DOE)
- DE-FG07-96ER14725
- Fonds pour la Formation de Chercheurs et l'Aide à la Recherche
- U. S. Global Change Fellowship
- Kodak
- Created
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2017-04-04Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field