Electron transfer at sensitized semiconductor electrodes [electronic resource].

Published:: Berkeley, Calif. : University of California, Berkeley, 1977.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Physical Description:: Pages: 150 : digital, PDF file
Additional Creators:: University of California, Berkeley and United States. Department of Energy. Office of Scientific and Technical Information

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Summary:

Electron transfer from the excited state of sensitizing dyes to the conduction band of semiconductors has been studied through photoelectrochemical techniques. Two systems were analyzed in detail: rhodamine B on ZnO and rose bengal on TiO/sub 2/. Prior to electrochemical experimentation, the adsorption characteristics of these dyes were investigated using ZnO, ZnS, and TiO/sub 2/ single crystals as substrates. Absorbance measurements of the adsorbed dye were taken as a function of the solution concentration of the dye. Adsorption isotherms heats of adsorption were also established; they were similar to literature data reported for adsorption of these dyes on powdered substrates. Using the absorbance data, the quantum efficiency for photoinjection of electrons from rhodamine B into a ZnO electrode was determined to be 2.7 x 10/sup -2/. This value was independent of the dye surface concentration down to 50% coverage of the electrode. With the assumption that not all of the rhodamine B adsorbed on the electrode has the same rate of electron injection, a kinetic model for the time decay of the photocurrent was developed; data were analyzed according to this theory. A rate constant for photoreduction of the adsorbed dye was determined for the reducing agents. 86 references.

Report Numbers:

E 1.99:lbl-6174
lbl-6174

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Note:

Published through SciTech Connect.
03/01/1977.
"lbl-6174"
Spitler, M.T.

Funding Information:

W-7405-ENG-48

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