Researchers from the University of Cambridge have developed an “artificial leaf”, capable of producing clean water and clean hydrogen fuel at the same time.
Taking inspiration from photosynthesis, the device is made up of a photocatalyst and nanostructured carbon mesh, which acts as a good absorber of light and heat. This then generates the water vapour the photocatalyst requires to produce hydrogen. The porous carbon mesh also keeps the device floating and away from the water below. This ensures that any contaminants do not interfere with the device’s functionality.
In an effort to use more of the sun’s power, the researchers have inserted a white, UV-absorbing layer on to the top of the device. This can aid the hydrogen production process through water splitting. The rest of the solar spectrum is then transmitted to the bottom of the device, where it vaporises the water. According to the researchers, the device has proven to be capable of producing clean water from highly polluted water, seawater and the River Cam in Central Cambridge, showcasing its potential to help address energy and water crises that many parts of the world find themselves facing.
Ariffin Mohamad Annuar, part of the research team and co-lead author of a paper into the device published in Nature Water, explained: “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. It’s such a simple design as well: in just a few steps, we can build a device that works well on water from a wide variety of sources. It’s so tolerant of pollutants, and the floating design allows the substrate to work in very cloudy or muddy water. It’s a highly versatile system.”
