Researchers have spent years trying to create devices that mimic the process of photosynthesis, where plants convert sunlight and carbon dioxide into fuel. The artificial leaves are able to use the sun to split water into hydrogen and oxygen, which can then be used as fuel for cars or electricity. A research team is now working to create fuels that are more energy dense.
Since nearly a hundred years, companies have produced synthetic fuels by mixing carbon monoxide with hydrogen at high temperatures. The hope is to eventually be able to do the same kind of synthesis using artificial leaves, which can harness the sun’s power.
The device created by the group produces ethylene, which is a hydrocarbon. This development may offer an easier, cheaper way to produce fuels, chemicals and plastics.
Virgil Andrei, a researcher at Cambridge University’s Department of Chemistry and Biochemistry, says the goal of this research is to develop fuels which do not leave a carbon footprint when they are burned. The process could produce fuels that are carbon-neutral, and reduce the need for fossil fuels.
Andrei, a co-author of a report published in Nature Catalysis In February. You don’t require additional fossil fuels because you mimic nature’s carbon cycle.
Copper nanoflowers
The team’s device, like other artificial leaves that harness energy from the Sun to create chemical product, uses the same principle. Hydrocarbons are more difficult to produce than hydrogen, because they require more energy.
The researchers used a number of innovations to achieve this. First, the researchers used a catalyst that was made of flower-like structures of copper, which were produced by the coauthor Peidong Yao at the University of California Berkeley. The nanoflowers were arranged on one side of this device to collect electrons. The electrons used were then converted into molecules such as ethylene, ethane and carbon dioxide.
Images of copper nanoflowers in the device.
ANDREI, V., ROH, I., LIN, JA. ET AL. ET AL.
The nanoflower structure is tunable, and can be adjusted in order to create a variety of molecules.
The team developed an energy-efficient method of generating electrons on the opposite side by processing glycerol with light-absorbing nanowires instead of water. The glycerol process also produces useful compounds such as glycerate and lactate. These can be used in cosmetics and pharmaceuticals.
Scaling Up
The trial system was successful, but it is just a step towards creating commercially viable fuel. Yanwei Lum is an assistant professor of chemical and biomolecular technology at National University of Singapore. She says, “This research proves that this concept works.” He adds that “the performance still isn’t sufficient for practical application.” “It’s not quite there.”
