학술논문

Photoelectrochemical Water Oxidation by Cobalt Catalyst ("Co—Pi")/α-Fe2O3 Composite Photoanodes: Oxygen Evolution and Resolution of a Kinetic Bottleneck.
Document Type
Article
Source
Journal of the American Chemical Society. 3/31/2010, Vol. 132 Issue 12, p4202-4207. 6p.
Subject
*PHOTOELECTROCHEMISTRY
*OXIDATION
*COBALT catalysts
*LIGHTING
*ELECTROLYTES
*BOTTLENECKS (Manufacturing)
*WATER electrolysis
Language
ISSN
0002-7863
Abstract
A cobalt-phosphate water oxidation catalyst ("Co-Pi") has been electrodeposited onto mesostructured α-Fe2O3 photoanodes. The photoelectrochemical properties of the resulting composite photoanodes were optimized for solar water oxidation under frontside illumination in pH 8 electrolytes. A kinetic bottleneck limiting the performance of such photoanodes was identified and shown to be largely overcome by more sparse deposition of Co-Pi onto the α-Fe2O3. Relative to α-Fe2O3 photoanodes, a sustained 5-fold enhancement in the photocurrent density and O2 evolution rate was observed at +1.0 V vs RHE with the Co-Pi/α-Fe2O3 composite photoanodes. These results demonstrate that integration of this promising water oxidation catalyst with a photon-absorbing substrate can provide a substantial reduction in the external power needed to drive the catalyst's electrolysis chemistry. [ABSTRACT FROM AUTHOR]