University of Cambridge researchers claim to have developed a ground-breaking device that can convert contaminated seawater into clean hydrogen fuel and purified water “anywhere in the world.”
What’s more interesting about this invention is the fact that the device sustainably sources its energy from solar.
How does it work?
According to the report, the concept of the solar-powered device is similar to the process of photosynthesis, where plants transform sunlight into food.
It also demonstrates a notable difference with “artificial leaf” technology that converts clean water to green hydrogen fuel. In contrast, the innovative device sources contaminated water to produce purified drinking water.
“Bringing together solar fuels production and water purification in a single device is tricky. Solar-driven water splitting, where water molecules are broken down into hydrogen and oxygen, need to start with totally pure water because any contaminants can poison the catalyst or cause unwanted chemical side-reactions.”
Dr Chanon Pornrungroj from Cambridge’s Yusuf Hamied Department of Chemistry (co-lead author)
Results
Remarkably, the device’s test results proved its ability to generate purified water from extremely contaminated water and seawater.
The results, published in the journal Nature Water, also emphasized that the device can also work even with the polluted River Cam in central Cambridge.
Professor Erwin Reisner’s research group members Pornrungroj and Mohamad Annuar developed the design by depositing a “photocatalyst on a nanostructured carbon mesh that is a good absorber of both light and heat.”
It essentially produces the water vapor the photocatalyst needs to generate hydrogen. Meanwhile, the porous carbon mesh aids the photocatalyst to float and ensures that impurities will not hamper the solar-powered devices’ functionality.
“The light-driven process for making solar fuels only uses a small portion of the solar spectrum – there’s a whole lot of the spectrum that goes unused.”
Co-lead author Ariffin Mohamad Annuar
They also employed a white, UV-absorbing layer above the device for hydrogen generation through water splitting. It will convert the excess light in the solar spectrum to the bottom part of the floating device that vaporizes the water.
“This way, we’re making better use of the light – we get the vapour for hydrogen production, and the rest is water vapour. This way, we’re truly mimicking a real leaf, since we’ve now been able to incorporate the process of transpiration.”
Dr Chanon Pornrungroj from Cambridge’s Yusuf Hamied Department of Chemistry (co-lead author)
Significance
The researchers asserted that the newly developed technology could significantly aid in providing clean hydrogen fuel and purified water in off-grid areas owing to its ability to function with any open water source. It also eliminates the need for external energy.
“In remote or developing regions, where clean water is relatively scarce and the infrastructure necessary for water purification is not readily available, water splitting is extremely difficult. A device that could work using contaminated water could solve two problems at once: it could split water to make clean fuel, and it could make clean drinking water.”
Co-lead author Ariffin Mohamad Annuar
Professor Reisner’s team is a significant boost in the global drive to combat the ongoing energy and water crises by generating clean hydrogen fuel and water simultaneously through solar power. However, the device remains a “proof of principle” as of today. The researchers have yet to determine how the technology can be applied to establish a genuine circular economy.
