Scientists create artificial plant that could spell the end of fossil fuels

The device mimics the ability of plants to convert light into clean energy, and can be easily and cheaply scaled up

A new device which mimics the ability of plants to photosynthesise could hasten the transition away from fossil fuels, say the Cambridge scientists who created it.

The test unit converts light, carbon dioxide and water into a clean and stable fuel that can either be used directly or converted into hydrogen.

It operates wirelessly and without an external power source, and despite being only three inches in size, it can be scaled up for use on an industrial level akin to solar farms, according to the researchers.

The quest to replicate photosynthesis has long been a challenge for science. The problem has been "converting as much of the sunlight as possible into the fuel you want, rather than be left with a lot of waste", said Dr Qian Wang of Cambridge's Department of Chemistry and lead scientist on the project.

Producing a scalable renewable fuel that can be easily stored and transported has also proved an intractable problem.

In 2019, Reisner Lab developed a solar reactor based on an artificial leaf design. It works similarly to the 2020 device from Cambridge by converting sunlight into clean fuel. However, a reliance on solar cell components means it is less scalable. The new test unit uses photosheet technology: sheets made up of semiconductor powders which can be prepared in large quantities, easily and cost-effectively.

“We were surprised how well it worked in terms of its selectivity – it produced almost no by-products,” said Dr Wang. “Sometimes things don’t work as well as you expected but this was a rare case where it actually worked better.”

Efficiencies still need to be improved before any commercial deployment can be considered. The researchers are now working to optimise further the system and improve efficiency. Additionally, they are exploring other catalysts for using on the device to get different solar fuels.