Floating solar device cleans water and creates energy

Image: Chris Boland, Unsplash

Researchers at the University of Cambridge, UK, have developed a device that can produce clean drinking water from polluted rivers and seawater using solar power.

The device uses a photocatalyst - a material that can convert solar energy into chemical energy - on a nanostructured carbon mesh to generate water vapour for hydrogen production, while also repelling water and contaminants. Its floating design means it works in very cloudy or muddy water.

Tests of the device showed it was able to produce clean water from highly polluted water, seawater, and from the River Cam in central Cambridge.

“The climate crisis and issues around pollution and health are closely related, and developing an approach that could help address both would be a game-changer for so many people.”

Prof Erwin Reisner, University of Cambridge

The team used a white UV-absorbing layer on top of the floating device for hydrogen production via water splitting - where water molecules are broken down into hydrogen and oxygen. The rest of the light in the solar spectrum is transmitted to the bottom of the device, which vaporises the water.

“Our device is still a proof of principle, but these are the sorts of solutions we will need if we’re going to develop a truly circular economy and sustainable future,” said Professor Erwin Reisner, who led the research. “The climate crisis and issues around pollution and health are closely related, and developing an approach that could help address both would be a game-changer for so many people.”

The floating solar-powered device. Image: University of Cambridge

This innovative technology has the potential to address both the energy and water crises facing many parts of the world, offering a sustainable solution for clean fuel and safe drinking water.

The research was supported in part by the European Commission’s Horizon 2020 programme, The European Research Council, the Cambridge Trust, the Petronas Education Sponsorship Programme, and the Winton Programme for the Physics of Sustainability.

The results are reported in the journal Nature Water.