Washington: Berkeley Lab researchers, working at the Joint Center for Artificial Photosynthesis (JCAP), have developed the first fully integrated microfluidic test-bed for evaluating and optimizing solar-driven electrochemical energy conversion systems.
This test-bed system has already been used to study schemes for photovoltaic electrolysis of water, and can be readily adapted to study proposed artificial photosynthesis and fuel cell technologies.
"We`ve demonstrated a microfluidic electrolyzer for water splitting in which all functional components can be easily exchanged and tailored for optimization. This allows us to test on a small scale strategies that can be applied to large scale systems," said Joel Ager, a staff scientist with Berkeley Lab`s Materials Sciences Division.
For more than two billion years, nature has employed photosynthesis to oxidize water into molecular oxygen. An artificial version of photosynthesis is regarded as one of the most promising of solar technologies.
JCAP is a multi-institutional partnership led by the California Institute of Technology (Caltech) and Berkeley Lab with operations in Berkeley (JCAP-North) and Pasadena (JCAP-South). The JCAP mission is to develop an artificial version of photosynthesis through specialized membranes made from nano-engineered materials that can do what nature does only much more efficiently and for the purpose of producing storable fuels such as hydrogen or hydrocarbons (gasoline, diesel, etc.).
"While there have been a number of artificial photosynthesis demonstrations that have achieved attractive solar to hydrogen conversion efficiencies, relatively few have included all of the operating principles, especially the chemical isolation of the cathode and anode," Ager said.
The microfluidic test-bed developed by Ager and his colleagues at JCAP-N allows for different anode and cathode materials to be integrated and electrically accessed independently through macroscopic contacts patterned in the outside of the microfabricated chip.
The transport of charge-carriers occurs through an ion conducting polymer membrane, and electrolysis products can be evolved and collected in separated streams. This general design provides selective catalysis at the cathode and anode, minimization of cross-over losses, and managed transport of the reactants.
Virtually any photoelectrochemical component, including those made of earth-abundant elements, can be incorporated into the test-bed.
Their work is described in a paper in the journal Physical Chemistry Chemical Physics (PCCP).