If you can pipe clean water to your home, consider yourself lucky—more than 660 million people worldwide lack access to safe drinking water. Now, the discovery of a new disinfection method has enabled Professor Yi Cui’s materials science and engineering lab to confront that problem head-on.
“We’d always been wanting to come up with an idea for water disinfection,” says Cui, although this latest finding, described in a recent paper, originated in a project to generate hydrogen gas from water, a process with renewable energy applications. Working with lead author and postdoctoral researcher Chong Liu, PhD ’15, Cui and his lab discovered an intriguing property of molybdenum disulfide, a common industrial lubricant, when it’s only a few atoms thick: Its edges become highly reactive. “That’s the cool thing about this material,” says Cui. By arranging microscopic ribbons of the compound edge up on glass plates and placing them in contaminated water, the team found the material can harness the energy in visible light to react with water molecules, producing hydrogen peroxide and other chemicals that kill bacteria. In early experiments, a device half the size of a postage stamp did so in about 20 minutes. There’s still plenty more testing to do, but they suspect the method will work on viruses, too.
As Cui says, “That’s the magic of doing material science.”
