Metal Oxides for
the Generation of Solar Hydrogen
Hematite (a-Fe2O3) is a promising material for sustainable generation of H2 due
to its low cost, widespread availability, chemical stability, and ability to absorb
a significant fraction of visible light. However numerous challenges remain in order
for this material to approach its theoretical potential of 15% solar to hydrogen
efficiency. The two most important metrics for photocurrent are its onset potential
and the current plateau. The former is limited by the kinetics of the oxygen evolution
reaction, while the latter is a measure of the fraction of photo-generated
carriers that can be extracted to perform water splitting. In this project we are
addressing these issues by controlling nanostrucure, doping, and interface engineering.
Nanowire arrays of hematite are synthesized from aqueous solution and subsequent
calcination. This scalable approach produces robust, uniform films using low cost
precursors. Through appropriate control of process conditions we have achieved significant
improvements in photocurrent response. Through further optimization of microstructure and
through the integration of electrocatalysts we hope to further enhance performance.
Dr. Rachel Moorish is leading our efforts in this
area with assistance from undergraduate Alex Sale.
for this project is being provided by Colorado Renewable Energy Collaboratory
through its Center for
Revolutionary Solar Photoconversion (CRSP) and the REMRSEC