A team of researchers at MIT published a paper in the Proceedings of the National Academy of Sciences that provides an in-depth investigation of an “artificial leaf” used for converting solar energy to hydrogen and of all parameters that could limit the efficiency of such system.
The artificial leaf was introduced in 2011 as a small device made entirely of earth-abundant, inexpensive materials that, like living leaves, can turn the energy of sunlight directly into a chemical fuel that can be stored and used later as an energy source. When placed in a container of water and exposed to sunlight, the device produces bubbles of hydrogen and oxygen. The leaf uses solar technology to convert sunlight into electricity and chemical catalysts to use the electric current to split atoms of hydrogen and oxygen from the water molecules surrounding them. This process allows solar energy to be stored for later use when the sun isn’t shining.
The MIT researchers looked at what can be expected with the technology currently available and the challenges that need to be confronted. Research has shown, since the original demonstration of the leaf the solar-to-fuel efficiencies have improved, showing great potential for the new device. However, there are some improvements to be made.
“Some of the most impactful papers are ones that identify a performance limit,” Tonio Buonassisi, associate professor of mechanical engineering, said. “We don’t always get it right…but such an analysis lays a roadmap for development and identifies a few ‘levers’ that can be worked on.”
The next step for MIT researchers: demonstrating these improvements on a functioning device. According to James Barber, professor of biochemistry at Imperial College London, if a proper demonstration can be achieved, “the construction of robust and efficient solar-driven modules which produce hydrogen from water on a large industrial scale would have considerable impact on human society.”
More info: Could an ‘Artificial Leaf’ Fuel Your Car?, npr.org