Artificial Leaf That Produces Fuel From CO2 And Sunlight

Conversations about the state of the planet’s climate are often dire and mostly negative, given the human-induced changes to it and the seeming inability to even control the degradation, let alone turn the clock back. And so, it should be cause for cheer that scientists from the University of Illinois at Chicago (UIC) have created a solar cell that converts atmospheric carbon dioxide into a usable fuel.

“The new solar cell is not photovoltaic — it’s photosynthetic,” Amin Salehi-Khojin, assistant professor of mechanical and industrial engineering at UIC, said. Salehi-Khojin, who is also the senior author of a related study published in the Science journal, added: “Instead of producing energy in an unsustainable one-way route from fossil fuels to greenhouse gas, we can now reverse the process and recycle atmospheric carbon into fuel using sunlight.”

The new solar cells can remove carbon dioxide, or CO2, from the atmosphere — like trees do — and farms that use such cells as artificial leaves “could produce energy-dense fuel efficiently,” according to the UIC website. The fuel produced by the cells is “synthesis gas, a mixture of hydrogen gas and carbon monoxide,” which “can be burned directly, or converted into diesel or other hydrocarbon fuels.”

Methods to convert CO2 to a burnable form of carbon have been around, but are inefficient and require precious metals like silver to be carried out. The device created by UIC researchers uses nanoflake tungsten diselenide, a material that is 20 times cheaper than its precious metal counterparts and works 1,000 times faster as a catalyst in the chemical reaction.

CO2 is a particularly pernicious greenhouse gas (water vapor is also a greenhouse gas, but you don’t hear anyone complaining about it) because it remains in the atmosphere longer than other gases that are released as a consequence of human activity, and therefore contributes significantly to trapping heat around the planet.