Lotus-inspired reactor turns carbon emissions into useful chemicals, fuel

Researchers at the University of Central Florida (UCF) in the US have taken inspiration from the lotus plant’s hydrophobic or water-repelling nature to make a highly efficient device that can convert carbon dioxide into useful products. The technology aims to reduce human activity’s carbon footprint while also sustainably producing more energy.

Inventors and scientists look curiously at nature since it is a treasure trove of inspiration for new projects and explanations of how the world around us works. Looking at animals and plants around us, we have developed technologies like airplanes and solar cells that provide faster transport and cleaner energy.

UCF researcher Yang Yang, who is also part of the university’s Renewable Energy and Chemical Transformation (REACT) Cluster, was working on a device to suck up planet-warming carbon dioxide gas from the atmosphere and turn it into useful products.

While other researchers have made similar attempts , Yang took inspiration from the lotus leaf to perfect his device.

The problem with the CO2 conversion process

To reduce the impact of greenhouse gases being emitted into the atmosphere, industries have been working on capturing the CO2 instead and keeping it stored for prolonged durations. The technique, while effective, is also cumbersome and carries the risk that the CO2 may someday be accidentally released back into the atmosphere.

Converting it to products such as methanol, ethanol, ethylene, acetate, or propanol is a much more useful and sustainable approach since these products are in high demand in the industry. To do this, captured CO2 is routed through an electrode and converted into these products.

Yang’s device combines both steps into one, capturing CO2 directly from the air and converting it into a useful product. However, the CO2 capture process also results in water condensation, which can interfere with the conversion step.

The presence of water during this reaction can prove to be quite a challenge. “If you have too much water surrounding your materials, you may produce hydrogen instead of converting carbon dioxide to chemicals,” said Yang in a statement. “That will decrease the energy efficiency of the overall process.”

If water is not separated from the surface of materials in this process, it can also flood the device, ending the CO2 conversion process.

Lotus-leaf inspiration

Taking inspiration from the hydrophobic, water-repelling surface of a lotus leaf, Yang conceived a device design in which water trickling down can be separated from the carbon dioxide conversion process.

His team fabricated a hydrophobic surface, similar to the lotus leaf, using a tin oxide film and fluorine layer. The device then extracts gaseous carbon dioxide via a bubbling electrode and selectively converts the CO2 into carbon monoxide and formic acid, which are used as raw materials for making other chemicals.

“The materials we use can repel the water from the surface, so we can avoid the formation of hydrogen, and we can greatly enhance the carbon dioxide reduction efficiency,” added Yang in the statement.” So that means eventually we can use almost all of the electricity for our reaction.”

Their technological device can be located at carbon-producing sites such as power plants, industries, and chemical production facilities to capture and convert CO2 directly from the air.

The research marks a significant initial step and is a foundational study that could lead to more extensive carbon dioxide capture techniques, according to Yang.

“For this, we validated our concept from the fundamental point of view,” he says. “We tested the performance in our reactors, but in the future, we want to develop a bigger prototype that can show people how quickly we can convert and reduce the carbon dioxide concentration and generate chemicals or fuels very quickly from our large-scale prototype.”

The research findings were published in the Journal of the American Chemical Society .