Energy From Sunlight and Synthetic Leaves

Atmospheric carbon dioxide is one of the largest global concerns we have. As a product of burning fossil fuels and a prominent source of climate change, one collective goal of most countries has been to reduce CO2 emissions. In recent years there has been significant advancements in clean and renewable energy sources of all kinds, but what if we could use the carbon dioxide we already have as fuel?

Research at the University of Illinois at Chicago and the U.S. Department of Energy’s Argonne National Laboratory, funded by the National Science Foundation and the U.S. Department of Energy, has resulted in a “potentially game-changing solar cell” that removes CO2 from the air and converts it directly into hydrocarbon fuel. “The new solar cell is not photovoltaic — it’s photosynthetic,’ says Amin Salehi-Khojin, assistant professor of mechanical and industrial engineering at UIC and senior author on the study.” The solar cell uses sunlight and metal compound called tungsten diselenide as a catalyst to power a photosynthesis-like process, but instead of producing sugars, like plants do for energy, these “artificial leaves” produces a mixture of hydrogen gas and carbon monoxide, Syngas. The Syngas can be burned directly, or converted into diesel or other hydrocarbon fuels. This process efficiently and cheaply recycles atmospheric carbon to be reused once again as fuel by using relatively inexpensive materials in the cell. Argonne researchers also point out that the process occurs with minimal lost energy, which is crucial to energy efficiency and lowers the energy cost of recycling the CO2.

Harnessing fuel from atmospheric CO2 at a cost comparable to the cost of gasoline could potentially leave fossil fuels obsolete. Amin Salehi-Khojin believes that the UIC artificial leaf technology will be adaptable to both large-scale use (like solar farms) and small-scale applications. Solar farms that use this technology would not only be able to produce recycled fuel, but also would remove substantial amounts of carbon dioxide from the atmosphere, sequestering carbon like a forest would. This budding technology is diverse enough to actively be fighting global warming by removing green house gasses from the atmosphere and by adding to renewable energy sources, and has the capability to be economically practical.