New design for artificial leaf absorbs 10 times more CO2 than natural leaves

A new technology for an artificial leaf designed by the University of Illinois—Chicago researchers could play a big role in cleaning up our air. The technology is particularly special because it was tested outside the lab in a natural setting, where it successfully pulled carbon dioxide — one of the key greenhouse gases contributing to global warming — from the air. Designs for artificial leaves so far have been tested in the lab using carbon dioxide (CO2) from pressurised CO2 tanks. The technology didn’t perform as well in the real world, where CO2 is a lot more dilute and mixed with all sorts of air-borne pollutants. Making the technology work in the real world has remained a big challenge in engineering artificial leaves, making the new study a promising new development in the field. The improved artificial leaf design proposed by researchers is at least ten times more efficient than natural leaves at harnessing energy from CO2. [caption id=“attachment_6084221” align=“alignnone” width=“1280”] Representational image. Image courtesy: Silk Leaf[/caption] In the new design, traditional artificial leaves are enclosed by a capsule that is filled with water. The capsule’s membrane is semi-permeable — very selective in allowing molecules to pass through it to the other side (i.e., the artificial leaf’s interior). When this setup is placed in sunlight, the water in the capsule warms up and evaporates through the membrane. Simultaneously, the capsule also draws in carbon dioxide from outside the membrane to replace the evaporating molecules of water. As the bionic leaf siphons more carbon dioxide inside the membrane, it gets converted to carbon monoxide (CO) and oxygen. The CO can be captured from the device and used to create synthetic fuels like  gasoline and methanol, and the oxygen released back into the environment. By enveloping the technology for an artificial leaf inside the specialised membrane, the whole setup can function outdoors just like a real leaf does, Maneesh Singh, the study’s lead researcher said in a press release. “Our conceptual design uses readily available materials and technology, that when combined can produce an artificial leaf that is ready to be deployed outside the lab where it can play a significant role in reducing greenhouse gases in the atmosphere,” said Singh. The study’s findings are published in the journal ACS Sustainable Chemistry & Engineering.