Wisconsin Alumni Research Foundation

Clean Technology
Clean Technology
More Efficient Water-Splitting Cells
WARF: P140325US01

Inventors: Kyoung-Shin Choi, Tae Woo Kim

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a method to synthesize high performance BiVO4 electrodes that can be used for harnessing solar energy.
N-type bismuth vanadate (BiVO4) has emerged as a promising photoanode for use in solar water-splitting cells given its favorable light absorption and conduction band characteristics. To date, however, efficiency levels hover far below what is expected because the material suffers from poor electron transport properties. Methods to address this problem by synthesizing porous BiVO4 have until now yielded large particles that hinder performance.
The Invention
UW–Madison researchers have developed a method for synthesizing nanoporous BiVO4 electrodes with large surface areas. The material is made up of a porous network of BiVO4 particles smaller than 150 nm and coated with oxygen evolution catalyst. The small size of the particles addresses prior drawbacks by increasing a property called electron–hole separation yield. The material is made by applying a vanadium solution to a type of bismuth crystal. The mixture is heated and converted into a porous network of BiVO4 particles.
  • Electrodes for use in solar cells that directly utilize solar energy to drive chemical reactions such as water splitting, CO2 reduction and biomass conversion.
Key Benefits
  • Improves solar-to-chemical conversion efficiency
  • Can be efficiently paired with any photocathode owing to its earlier photocurrent onset and a high fill factor
  • Promising results using inexpensive materials and simple production methods
  • Small particle size
  • Large surface area
Stage of Development
The new electrodes have demonstrated superior electron-hole separation yields (.90 at 1.23 V versus RHE).
Additional Information
For More Information About the Inventors
  • Kim T.W. and Choi K-S. 2014. Nanoporous BiVO4 Photoanodes with Dual-Layer Oxygen Evolution Catalysts for Solar Water Splitting. Science. 343, 990-994.
For current licensing status, please contact Jennifer Gottwald at [javascript protected email address] or 608-960-9854