Electrolysis of water at strontium titanate (SrTiO₃) photoelectrodes: distinguishing between the statistical and stochastic formalisms for electron-transfer processes in fuel-forming photoelectrochemical systems
Abstract
Conventional photoelectrochemical and photovoltaic theory predicts a light intensity threshold for sustaining the net electrolysis of water using semiconductor electrodes, but a stochastic charge-transfer formalism for photoelectrolysis reactions does not predict such threshold behavior. This work examines the theoretical and experimental aspects of light-assisted water electrolysis using n-type SrTiO₃/H₂O interfaces. A theoretical framework, based upon simple chemical kinetic considerations, has been formulated to describe the behavior of such photoelectrosynthetic cells. Experiments conducted on the n-SrTiO₃/5.0 M NaOH(aq)/Pt photoelectrosynthetic cell have revealed a threshold in the short-circuit electrolysis current at 5 X 10⁻⁵ W/cm² of 325-nm illumination. Additional theory and experiments have provided insight into relationships between two-electrode regenerative photoelectrochemical cells, two-electrode photoelectrosynthetic cells, and three-electrode potentiostatic cells. These experiments and theory indicate that a conventional chemical kinetic treatment of interfacial electron-transfer rates appears to be sufficient to describe the photoelectrochemical behavior of SrTiO₃ and TiO₂/aqueous junctions.
Additional Information
© 1992 American Chemical Society. We thank the National Science Foundation, Grant CHE-8814263, for support of this work. A.K. also is grateful to the U.S. Department of Education for a graduate fellowship.Additional details
- Eprint ID
- 121037
- Resolver ID
- CaltechAUTHORS:20230419-953397000.29
- NSF
- CHE-8814263
- Department of Education
- Created
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2023-04-26Created from EPrint's datestamp field
- Updated
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2023-04-26Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Division of Chemistry and Chemical Engineering
- Other Numbering System Identifier
- 8471