This device uses visible sunlight to disinfect water

Using the sun to disinfect water is nothing new; UV rays start killing bacteria after six hours, although the process can take up to 48 hours. It’s time-consuming, but often an only option in developing countries. Researchers at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University's Institute for Materials and Energy Science created a device to speed up that process. Their findings were published in Nature Nanotechnology earlier this week. The device