While a small number of hydrogen vehicles are already being tested and developed, the current costs associated with hydrogen production persist. However, that could soon end as scientists from the University of Wisconsin-Madison have come up with an affordable method of producing hydrogen.
When people think of using the Sun as an energy source, solar energy is often the first thing that comes to mind. However, the power of the sun can also be used in other ways. A team of researchers has figured out how to use the Sun's energy to produce hydrogen in an affordable manner.
Chemical fuels, such as hydrogen, can be used to produce electricity using chemically driven reactions. However, the costs associated with hydrogen fuel cells still far outweigh the costs of using more conventional sources of energy such as fossil fuels.
"In order to make commercially viable devices for solar fuel production, the material and the processing costs should be reduced significantly while achieving a high solar-to-fuel conversion efficiency," says University of Wisconsin-Madison chemistry professor Kyoung-Shin Choi.
Choi and her colleague Tae Woo Kim, a postdoctoral researcher from the same university, were able to use solar energy to extract hydrogen from water. The pair used affordable oxide-based materials to make it possible to use solar energy to split water into oxygen and hydrogen. The scientists published their findings on the online journal Science.
Moreover, the researchers achieved a solar-to-hydrogen conversion efficiency of 1.7 percent. This is currently the highest recorded efficiency for systems using solar energy and oxide-based materials.
"Without fancy equipment, high temperature or high pressure, we made a nanoporous semiconductor of very tiny particles that have a high surface area," says Choi. "More surface area means more contact area with water, and, therefore, more efficient water splitting."
There are many concurrently running research projects that deal with both solar energy systems and hydrogen extraction. However, the semiconductor-catalyst system that the researchers used in their study has seen little interest in other scientific institutions.
"The problem is, in the end you have to put them together," Choi says. "Even if you have the best semiconductor in the world and the best catalyst in the world, their overall efficiency can be limited by the semiconductor-catalyst interface."
While more work is needed to improve the system, other technologies such as hydrogen fuel cell manufacturing and large scale hydrogen extraction methods also need to reach certain levels of maturity before hydrogen fuel becomes a mainstay of everyday life.
