Current-voltage and spectral response properties were determined for polycrystalline n-GaAs photoanodes in contact with aqueous KOH-Se-/2- and nonaqueous CH3CN-ferrocene+/0-LiClO4 electrolytes. The n-GaAs/KOH-Se-/2- system initially exhibited poor junction behavior, but chemisorption of RuIII, RhIII, IrIII, CoIII, or OsIII ions onto the GaAs photoanode was found to yield improved I-V properties. The trend in I-V improvement correlated with improved electrocatalysis of Se2- oxidation at p-GaAs, n+-GaAs, and In2O3 electrode surfaces. The n-GaAs/CH3CN system displayed excellent junction behavior and did not respond to metal chemisorption treatments. These results are consistent with the metal-ion-induced improvement being predominantly due to electrocatalytic effects.
|Number of pages||5|
|Journal||Journal of Physical Chemistry|
|Publication status||Published - Oct 6 1988|
ASJC Scopus subject areas
- Physical and Theoretical Chemistry