Original news release was issued by the Argonne National Laboratory
The Earth is our home, there is no denying that. It has served us as a shelter for millions of years, providing all the proper conditions and means there are to preserve the human species. With so many factors to be treasured, humans haven’t been known to hold the planet in such a high regard, contributing to worldwide threats like global warming by burning the fossil fuels in power plants and car engines. While trees and other plants are able to cope with the abundance of carbon dioxide by slowly converting it in to energy through photosynthesis, scientists from the U.S. Department of Energy’s Argonne National Laboratory and the University of Illinois at Chicago have also found a similar way to convert carbon dioxide into a usable energy source using sunlight.
The research team was able to construct an “artificial leaf” that could transform carbon dioxide into a usable fuel. One of the major issues is that carbon dioxide is relatively chemically unreactive. Researchers had to find a catalyst — a particular compound that could make carbon dioxide react more readily. They succeeded by using a metal compound called tungsten diselenide, which allowed them to convert carbon dioxide in to carbon monoxide which scientists are already able to turn in to usable fuel, such as methanol. The study proved the reaction is very efficient — with minimal lost energy.
“Making fuel from carbon monoxide means travelling ‘downhill’ energetically, while trying to create it directly from carbon dioxide means needing to go ‘uphill,'” said Argonne physicist Peter Zapol, another author of the study.
The setup for the reaction is sufficiently similar to photosynthesis. In the first step incoming photons — packets of light — are converted to pairs of negatively-charged electrons and corresponding positively-charged “holes” that then separate from each other. In the second step, the holes react with water molecules, creating protons and oxygen molecules. Finally, the protons, electrons and carbon dioxide all react together to create carbon monoxide and water. According to Curtiss, the tungsten diselenide catalyst is also quite durable, lasting for more than 100 hours — a high bar for catalysts to meet.
Nature has all the tricks up it’s sleeve for a more sufficient world, the one less dependable on fossil fuels. It is up to us to open our eyes and get inspired. Resources all over the globe are expendable and Argonne researchers (and not only them, as we have reported before) are on the right track to find an economical way to make chemical fuels reusable with the help of sunlight.