A group of European scientists, coordinated by a team from the Collège de France ( Chemistry of Biological Processes chair), have created a device that, like plants, convertsCO2, water and sunlight into fuels and high value-added chemicals.
This new all-in-one device mimics plant photosynthesis and is produced with simple, environmentally-friendly manufacturing processes using abundant materials. The study, just published in the prestigious American scientific journal Proceedings of the National Academy of Sciences (PNAS, T. Huan et al. , March 25, 2019 - DOI: 10.1073/pnas.1815412116), reports a record efficiency of 2.3% for the production of hydrocarbons from sunlight, while using only cheap and easy-to-implement materials. Such artificial plants bring us closer to a closed-cycle economy, where fuels would be produced from the same carbon dioxide produced by burning them.
"Other similar systems use very expensive metals such as iridium and silver, but we don't need them here," explain study co-authors Victor Mougel (Professor at the Laboratory of Inorganic Chemistry, ETH Zürich) and Marc Fontecave (Professor at the Collège de France, holder of the Chemistry of Biological Processes Chair). "Our device is designed with metals abundant on earth, cheap materials and containing no ores from conflict zones," they add. "In addition, we have managed to integrate all the system components into a single device that is very simple to manufacture (...) We have succeeded in making an inexpensive device that converts sunlight and carbon dioxide from fuels and into useful chemicals."
Plants live by photosynthesis. They obtain water and carbon dioxide from the air, and convert them into sugars using solar energy. The new device imagined by these researchers mimics plants, usingCO2, water and sunlight to produce fuels and high-value-added chemicals. Such approaches had been tried before, but now the researchers have succeeded in surpassing plants - their process is twice as efficient as plants - using only low-cost materials. The new device converts 2.3% of the sun's energy into hydrocarbons.
One of the key elements of this new artificial plant is the technology used in its "leaves" - the solar cells that capture light and convert it into energy. "Classically developed systems use solar panels that are very expensive and contain dangerous chemicals such as gallium, indium and even arsenic," says Federico Bella (researcher at Turin Polytechnic Institute and co-author of the study). "Our approach uses perovskite solar cells that are both cost-effective and water-resistant, making our device ready for use in real-life conditions," he adds. "What's more, our perovskite solar cells can be simply printed onto any surface," explains Bella. "Forget about expensive silicon-based solar cells that are difficult to produce in cleanrooms," he says. "We just need a printer, a glass or plastic support, to prepare them!"
Finally, because the device uses carbon dioxide as the sole source of carbon to produce fuels and useful chemicals, it could eventually lead to a sustainable solution to the build-up of greenhouse gases in our atmosphere. Plants produce sugars, but these devices produce high-value fuels and chemicals that can be fed into our existing supply chains. "Such devices bring us closer to a closed-cycle economy," say Mougel and Fontecave. "Imagine a world where fuels were sourced from the same carbon dioxide produced by their combustion (...) Potentially, we could stop carbon dioxide emissions and limit climate change."
