Researchers have in two years nearly doubled the number of materials with potential for use as a water-splitter to create solar fuels thanks to a new process they developed that speeds their discovery.
Scientists at the California Institute of Technology and Lawrence Berkeley National Laboratory (Berkeley Lab) have identified a high-throughput method of identifying materials called photoanodes—which can split water using visible light as an energy source—for the development of commercially viable solar fuels.
The method combines computational and experimental approaches--first mining a materials database for potentially useful compounds, screening it based on the properties of the materials, and then testing the most promising candidates using high-throughput experimentation, researchers said. Previously, they relied on a rigorous process that required testing of individual compounds to assess their potential for use in specific applications.
The work is significant because over the past 40 years, researchers have found only 16 photoanode materials for the development of solar fuels. In the last two years, the Caltech-Berkeley Lab team have identified 14—nearly twice that.
“The key advance made by the team was to combine the best capabilities enabled by theory and supercomputers with novel high-throughput experiments to generate scientific knowledge at an unprecedented rate,” said Caltech’s John Gregoire, one of the lead researchers.
|Scientists at the California Institute of Technology (Caltech) and the Lawrence Berkeley National Laboratory created new materials that have potential for use in solar fuels by a new method that combined computational and traditional testing methods, including spraying combinations of elements onto thin plates. (Source: Caltech)|
Berkeley Lab's Jeffrey Neaton and Qimin Yan also worked on the project, which was a partnership between the Joint Center for Artificial Photosynthesis (JCAP) at Caltech and Berkeley Lab's Materials Project. The team used resources at the Molecular Foundry and the National Energy Research Scientific Computing Center.
Researchers published a paper about their work in the journal Proceedings of the National Academy of Sciences .
The development of solar fuel is a Holy Grail of sorts for clean-energy research. These fuels are created using only the natural elements of sunlight, water, and carbon dioxide, and are a completely clean alternative to coal, oil, and other fossil fuels that cause pollution and are harmful to the environment.
Researchers have been exploring a range of fuels from hydrogen gas to liquid hydrocarbons, but need a material that can act as a solar-powered catalyst—or photoanode—to split water is required for their production, which is why they are constantly seeking new photoanodes for this purpose.
The Caltech-Berkeley team explored 174 metal vanadates—compounds containing the elements vanadium and oxygen along with one other element from the periodic table. Their work reveals how different choices for this third element can produce materials with different properties and how to "tune" those properties to make a better photoanode, Gregoire said.
Elizabeth Montalbano is a freelance writer who has written about technology and culture for more than 15 years. She currently resides in a village on the southwest coast of Portugal.