Chemically derivatized n-type silicon photoelectrodes. Stabilization to surface corrosion in aqueous electrolyte solutions and mediation of oxidation reactions by surface-attached electroactive ferrocene reagents

Journal Article · Tue Mar 13 23:00:00 EST 1979 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00500a004· OSTI ID:6294371

Bolts, J M; Bocarsly, A B; Palazzotto, M C; Walton, E G; Lewis, N S; Wrighton, M S

Derivatization of n-type Si photoelectrode surfaces with (1,1'-ferrocenediyl)dichlorosilane results in the persistent attachment of photoelectroactive ferrocene species. Derivatized surfaces have been characterized by cyclic voltammetry in EtOH or H/sub 2/O electrolyte solutions. Such surfaces exhibit persistent oxidation and reduction waves, but the oxidation requires illumination as expected for an n-type semiconductor. The oxidation wave is observed at potentials approx. 300 mV more negative than at Pt, reflecting the ability to oxidize ferrocene contrathermodynamically by irradiation. Derivatized n-type Si can be used to sustain the oxidation of solution-dissolved ferrocene under conditions where naked Si is incapable of doing so. Further, derivatized n-type Si has been used in an aqueous electrolyte to oxidize Fe(CN)/sub 6//sup 4 -/. Finally, the photooxidation of solution species has been demonstrated to occur via photogeneration of holes in the Si, oxidation of the surface-attached species, and then oxidation of the solution species by the surface-attached oxidant, providing the first direct proof of mediated electron transfer for any derivatized electrode. Derivatized electrodes can be used to sustain the conversion of light to electricity but the efficiencies are low. Based on results for 632.8-nm irradiation, solar energy conversion efficiencies of approx. 1% can be obtained. 7 figures, 1 table.

• Research Organization: Massachusetts Inst. of Technology, Cambridge
• OSTI ID: 6294371
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 101:6; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505 -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400400* -- Electrochemistry
ALCOHOLS
AQUEOUS SOLUTIONS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CHLORINE COMPOUNDS
COMPLEXES
CONVERSION
CORROSION RESISTANCE
DISPERSIONS
ELECTRODES
ELECTRON TRANSFER
ELEMENTS
ENERGY CONVERSION
ETHANOL
HALOGEN COMPOUNDS
HOLES
HYDRIDES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
IRON COMPLEXES
MIXTURES
ORGANIC COMPOUNDS
OXIDATION
REDUCTION
SEMIMETALS
SILANES
SILICON
SILICON COMPOUNDS
SOLAR ENERGY CONVERSION
SOLUTIONS
STABILITY
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
VOLTAMETRY