A micrograph shows the surface of a light-activated catalyst that disinfects water even in the dark.
Getting access to clean drinking water is an ongoing problem for people in developing countries. And even cities that have good water-treatment systems are looking for better ways to deliver safer, cleaner water. Now an international research team has developed a photocatalyst that promises quick, effective water disinfection using sunlight or artificial light. What’s more, the photocatalyst keeps working after the light is turned off, disinfecting water even in the dark.