Solar breakthrough turns CO2 into burnable fuel

29 Jul 2016

A potentially gamechanging breakthrough has been made in solar cell technology with the creation of cells that can cheaply and efficiently turn atmospheric CO2 into hydrocarbon fuel.

Current technology used in solar farms across the world takes sunlight and converts it into energy that needs to be stored in huge batteries, but this new University of Illinois at Chicago discovery can solve two environmental issues at once.

While solar energy in its current state solves the problem of sourcing energy from renewable sources, this new method not only creates burnable hydrocarbon fuel from CO2, but can source it directly from the harmful atmospheric CO2.

Making fossil fuels obsolete

If an entire farm of these ‘artificial leaves’ – as the researchers call the device – were spread across a large area, they could remove significant quantities of harmful CO2, while also creating energy-dense fuel efficiently.

Photosynthesising plants produce sugar as their fuel, but this artificial leaf device creates a synthetic gas that contains a mixture of hydrogen and carbon monoxide which can be easily converted into diesel or other hydrocarbon fuels.

“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,” said Amid Salehi-Khojin, senior researcher on the study.

If this technology could produce quantities at a price similar to current fossil fuels, it could have a major impact that would see those harmful fuels quickly become obsolete in favour of the cleaner-sourced fuel.

Solar cell

Simulated sunlight powers a solar cell that converts atmospheric CO2 directly into synthetic gas. Photo via University of Illinois at Chicago/Jenny Fontaine

Could be used on Mars

Publishing their findings in Science, the Chicago team worked on a number of potential catalysts to create the solar fuel, finally settling on one called nanoflake tungsten diselenide.

This new catalyst, said the paper’s first author Mohammad Asadi, is 1,000-times faster than noble-metal catalysts and around 20-times cheaper, far outstripping previous attempts.

The researchers add that this technology – perhaps most importantly for producing fuel en masse – is not only adaptable for large-scale use in solar farms, but could also be used for small-scale applications.

Such small-scale applications could have ramifications outside of our own planet as, Salehi-Khojin suggested, the artificial leaves could be used on Mars by future astronauts, taking advantage of the planet’s CO2-rich atmosphere.

Flower with car image via Shutterstock

Colm Gorey was a senior journalist with Silicon Republic