A team from the University of Cambridge developed this device, which mimics photosynthesis, the ability of plants to convert sunlight into energy. Photo by University of Cambridge
Aug. 24 (UPI) -- Engineers at the University of Cambridge have developed a device that converts sunlight, carbon dioxide and water into a carbon-neutral fuel, without the need for electrical components.
The technology could pave the way for artificial photosynthesis, replicating plants' ability to convert sunlight into energy. The new device utilizes what's called a photocatalyst sheet, which harnesses the power of the sun to convert CO2 and H2O into O2 and formic acid, a storable fuel.
According to a new paper published Monday in the journal Nature Energy, the technology could be deployed on scales similar to solar farms, converting large amounts of carbon dioxide into clean fuel.
"It's been difficult to achieve artificial photosynthesis with a high degree of selectivity, so that you're converting as much of the sunlight as possible into the fuel you want, rather than be left with a lot of waste," Qian Wang, Cambridge chemist and first author of the new study, said in a news release.
Several technologies used for production of carbon-neutral fuel also yield a variety of byproducts. Separating byproducts from fuel is an expensive and energy-intensive process, making the production of so-called clean fuel not so clean.
"We want to get to the point where we can cleanly produce a liquid fuel that can also be easily stored and transported," said Erwin Reisner, Cambridge professor and the paper's senior author.
An artificial leaf device created by Reisner's research group served as the inspiration for the new device.
The artificial leaf converted sunlight, carbon dioxide and water into a fuel called syngas. The new technology uses a slightly different technique for energy conservation, yielding folic acid instead of syngas.
Instead of the solar cell components used to build the artificial leaf, engineers relied on an array of photocatalysts embedded in a sheet composed of semiconductor powders. The photocatalyst sheet production process is inexpensive and can be easily scaled, according to researchers.
Authors of the new study suggest the formic acid produced by the device can be captured in a solution and easily converted into a variety of fuel types.
"We were surprised how well it worked in terms of its selectivity - it produced almost no by-products," said Wang. "Sometimes things don't work as well as you expected, but this was a rare case where it actually worked better."
Though scientists predict their technology can be easily scaled, it's not quite ready for prime-time. They are currently experimenting with different combinations of photocatalysts to improve the device's stability and efficiency.
"We hope this technology will pave the way toward sustainable and practical solar fuel production," said Reisner.
