Experts develop a wireless device that makes clean fuel from sunlight, CO2 and water

October 26, 2020
Cambridge, England
Researchers have developed a wireless device that converts sunlight, carbon dioxide and water into a carbon-neutral fuel, without requiring any additional components or electricity.
Development of Artificial Photosynthesis is a step closer with this research. Botanists term photosynthesis as the ability of green plants to convert sunlight into energy.
A team from the University of Cambridge collaborated with University of Tokyo Professor Kazunari Domen’s team to develop this device, according to a report published by Science Daily.
Domen is co-author of the paper along with first author lDr Qian Wang and senior author Professor Erwin Reisner.
The device, based on an advanced ‘photosheet’ technology, converts sunlight, carbon dioxide and water into oxygen and formic acid — a storable fuel that can be either be used directly or be converted into hydrogen.
The journal Nature Energy published a report on this finding. This research represents a new method of converting carbon dioxide into clean fuels.
Energy farms could use a higher version of the wireless device to produce clean fuel using sunlight and water. Energy farms are similar to solar farms that produce clean energy.
Harvesting solar energy to convert carbon dioxide into fuel is a promising way to reduce carbon emissions and transition away from fossil fuels.
The challenge, experts face, is producing clean fuel without unwanted by-products.
Cambridge Department of Chemistry and first author of the paper Dr Qian Wang says, “It’s difficult to achieve artificial photosynthesis with a high degree of selectivity where we convert as much of the sunlight as possible into fuel, rather than a lot of waste.”
The paper’s senior author Professor Erwin Reisner says, “Storage of gaseous fuels and separation of by-products can be complicated. We want to get to the point where we can cleanly produce a liquid fuel that can also be easily stored and transported.”
In 2019, researchers from Reisner’s group developed a solar reactor based on an ‘artificial leaf’ design. It uses sunlight, carbon dioxide and water to produce a fuel, known as syngas. The new technology looks and behaves quite similarly to the artificial leaf but works in a different way and produces formic acid.
While the artificial leaf used components from solar cells, the new device does not require these components and relies solely on photocatalysts embedded on a sheet to produce a so-called photocatalyst sheet. The sheets comprise semiconductor powders that can be prepared in large quantities easily and cost-effectively.
This new robust technology produces clean fuel that is easy to store and shows potential for producing fuel products at higher scale. The test unit is 20 square centimetres in size, but the researchers say that it should be relatively straightforward to scale it up to several square metres. They say formic acid can be stored in solution and chemically converted into different types of fuel.
“We were surprised how well it worked in terms of its selectivity — it produced almost no by-products,” says Dr Wang. “Sometimes things do not work as well as you expect, but this was a rare case where it actually worked better.”
The carbon dioxide converting cobalt-based catalyst is easy to make and relatively stable. While this technology will be easy to scale up than the artificial leaf, the efficiencies need improvements before considering commercial deployment. The researchers are experimenting with a range of different catalysts to improve both stability and efficiency.
The researchers are now working to further optimise the system and improve efficiency. They are exploring other catalysts for using on the device to get different solar fuels.
“We hope this technology will pave the way towards sustainable and practical solar fuel production,” says Reisner.
Story Source: University of Cambridge. The original story has Creative Commons License.