Researchers in Belgium have developed a device that uses sunlight to purify the polluted air and also produces hydrogen gas that can be stored and used for power. "We couple both processes together in one device," Sammy Verbruggen, a professor of bioscience engineering at the University of Antwerp, told Live Science. "Hydrogen production on one side and air purification on the other side," added Verbruggen.
Professor Verbruggen is working on the device with two teams that were separately developing the device for years. While one team the University of Antwerp the scientists had been testing different paths of combining light energy with nanomaterials in order to purify the air, the other team had been working on a tiny fuel cell with a membrane that could produce hydrogen gas from water at the University of Leuven, reported Live Science.
Now both the teams have merged their expertise and finally created this device which can do both at the same time.
Professor Verbruggen said that the scientists are mainly focusing on air that is polluted with volatile organic compounds (VOCs), which are small molecules produced by chemicals in adhesives, upholstery, carpeting, copy machines, cleaning fluids and more. In present in enough concentrations, VOCs can cause severe health problems, such as headaches, eye irritation, dizziness, nausea and asthma attacks.
According to the Environmental Protection Agency, VOCs can be found in the air of buildings, which were enclosed for a period of time and now are well ventilated, which might include newly built high-rises to factories that manufacture goods like paint and carpeting. Verbruggen also added that "They can lead to a disease called the sick building syndrome."
The prototype cell that has been created by the researchers is a square with an active area that measures about 0.4 inches by 0.4 inches. At one side of the device, a tube delivers polluted air into the cell, while the light enters naturally through a transparent window that covers a membrane treated with a light-activated catalyst. Once polluted air and light meet at the membrane in the device, the catalyst tears apart the small organic molecules. In the process, protons get free and seep through the membrane, collecting on the other side. According to researchers, here a platinum catalyst converts them into hydrogen gas and meanwhile, the purified air exits through the second tube attached to the device.
The researchers have been able to purify air and create gas using several organic compounds, such as methanol, ethanol and acetic acid. They are now also performing tests with acetaldehyde, a liquid that is used in the making of acetic acid and perfumes.
"You can purify the waste streams so that they meet their environmental quota and at the same time recover the energy that was stored in those molecules," Verbruggen said. The gas produced can be used to power lights or other machines in factories, he added.
As of now, the team has not been able to develop an engineering solution to collect and store the produced hydrogen gas. However, scientists are working on it. "I'm more motivated to improve the cell's performance, right now," said Verbruggen.