Rate of reduction of photogenerated, surface-confined ferricenium by solution reductants: derivatized n-type silicon photoanode-based photoelectrochemical cells
In this article researchers wish to amplify on previous studies of derivatized photoanode surfaces by reporting new results related to the measurement of k/sup et/ for n-type Si photoanodes derivatized with (1,1'-ferrocenediyl) dichlorosilane, I. researchers report that a number of solution reductants B can be oxidized by the photogenerated, surface-confined ferricenium with a value of k/sub et/ that exceeds 6 x 10/sup 8/ cm/sup 3/ mol/sup -1/ s/sup -1/ at 298 K. Larger values of k/sub et/ cannot be measured owing to difficulties associated with mass transport controlled rates. This would correspond to a homogeneous bimolecular rate constant of > 6 x 10/sup 5/ M/sup -1/ s/sup -1/. In practical terms this means that k/sub et/ is large enough to yield a good value of Phi/sub e/ at solar irradiation intensities and at generally accessible concentrations of B. However, the extent to which the oxidation of B can be driven uphill, E/sub V, is generally modest compared to E/sug g/ = 1.1 eV for Si. Small values of E/sub V give low overall optical energy conversion efficiency.
- Research Organization:
- Massachusetts Inst. of Tech., Cambridge
- OSTI ID:
- 5592152
- Journal Information:
- ACS Symp. Ser.; (United States), Journal Name: ACS Symp. Ser.; (United States) Vol. 146; ISSN ACSMC
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
140505* -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
ANODES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
COMPARATIVE EVALUATIONS
CURRENTS
DERIVATIZATION
ELECTRIC CURRENTS
ELECTROCHEMICAL CELLS
ELECTROCHEMISTRY
ELECTRODES
ELEMENTS
EQUIPMENT
HALIDES
HALOGEN COMPOUNDS
IODIDES
IODINE COMPOUNDS
IRON COMPOUNDS
KINETICS
MATERIALS
N-TYPE CONDUCTORS
PHOTOANODES
PHOTOCHEMICAL REACTIONS
PHOTOCURRENTS
PHOTOELECTROCHEMICAL CELLS
PHOTOSYNTHESIS
REACTION KINETICS
REDOX REACTIONS
REDUCING AGENTS
REDUCTION
SEMICONDUCTOR MATERIALS
SEMIMETALS
SILICON
SOLAR EQUIPMENT
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
VOLTAMETRY