Synthesis and characterization of a photosensitive interface for hydrogen generation: Chemically modified p-type semiconducting silicon photocathodes
Abstract
p-Si photocathodes functionalized first with an N,N′-dialkyl-4,4′-bipyridinium redox reagent, (PQ^(2+/+-))_(surf), and then with a Pt precursor, PtCl₆²⁻, give significant efficiency (up to 5%) for photoelectrochemical H₂ generation with 632.8-nm light. Naked p-Si photocathodes give nearly zero efficiency, owing to poor H₂ evolution kinetics that are improved by the (PQ^(2+/+-))_(surf)/Pt modification. The mechanism of H₂ evolution from p-Si/(PQ^(2+/+-))_(surf)/Pt is first photoexcitation of electrons to the conduction band of Si followed by (PQ²⁺)_(surf) → (PQ⁺⁻)_(surf) reduction. The dispersion of Pt then catalyzes H₂O reduction to give H2 and regeneration of (PQ²⁺)_(surf). The overall energy conversion efficiency rivals the best direct optical to chemical conversion systems reported to date.
Additional Information
© 1980 National Academy of Sciences. We thank the United States Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, for support of this research. N.S.L. acknowledges support as a John and Fannie Hertz Predoctoral Fellow, 1977 to present, and M.S.W. acknowledges support as a Dreyfus Teacher-Scholar Grant recipient, 1975-1980. Partial support from the Massachusetts Institute of Technology Laboratory for Computer Science, IBM Fund, is gratefully acknowledged.Attached Files
Published - pnas00498-0033.pdf
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Additional details
- PMCID
- PMC350266
- Eprint ID
- 120849
- Resolver ID
- CaltechAUTHORS:20230413-768824000.34
- Department of Energy (DOE)
- Fannie and John Hertz Foundation
- Camille and Henry Dreyfus Foundation
- Massachusetts Institute of Technology (MIT)
- Created
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2023-04-18Created from EPrint's datestamp field
- Updated
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2023-04-18Created from EPrint's last_modified field