Semiconductor-based interfacial electron-transfer reactivity: Decoupling kinetics from pH-dependent band energetics in a dye-sensitized titanium dioxide/aqueous solution system

Journal of Physical Chemistry

Volumn 100, Issue 17, 1996, Pages 6867-6870

  Yan, Susan G ^a   Hupp, Joseph T ^a  

^a NORTHWESTERN UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 33748606923     PISSN: 00223654     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp953180l     Document Type: Article

References (35)

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24. -1), however, makes the former difficult to detect under the conditions of our experiment.
25. As expected, at lower pH the slow component is lost at less positive potentials (e.g., -0.7 V at pH = 2.4).
26. CB. Fits to a more complex function (two exponentials plus a constant) also yielded a pH invariant fast component.
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30. 2 under accumulation conditions (i.e., rapid quenching is absent; see: O'Regan, B.; Moser, J.; Anderson, M.; Grätzel. M. J. Phys. Chem. 1990, 94, 8720).
31. 4-, were suggestive of behavior similar to that for the phosphonated dye but were complicated by desorption at extreme pH's.
32. short was ca. 45 ns. Consistent with results shown in Figure 4, the decay time proved to be pH independent over the range from 2 (the lowest pH examined) to 10 (the highest pH examined).
33. 2 see: Finklea, H., Semiconductor Electrodes; Elsevier, New York, 1988, Chapter 2.
34. At the suggestion of a reviewer, we also examined ET kinetics in the absence of solvent. (No attempt was made, however, to remove chemisorbed water.) Results similar to those shown in Figure 2 were obtained.
35. 3 can be turned on and off via pH changes. In view of the present findings, transient studies of this system could be very informative.