Cleaning up with sunshine

This article describes how solar photocatalytic technology can be an effective method of breaking up toxic chemicals and disinfecting both water and air. The use of solar energy for the production of food, fiber, and heat has been known to mankind for a long time. Research over the last five decades has also made it possible to produce mechanical and electrical power with solar energy. And although the potential of solar radiation for disinfection and environmental mitigation has been known for years, only recently has this technology been scientifically recognized and researched. For anyone who has observed colors fading over long exposure to sunlight, certain materials deteriorating in the sunlight, or skin getting sunburned, it is not hard to imagine sunlight causing reactions that could be used beneficially to break up toxic chemicals. Older civilizations considered it essential that human dwellings be designed to allow sunshine in. This may have been for disinfection or to keep the growth of microorganisms in check. Research over the last three decades has not only confirmed the capability of sunlight for detoxification and disinfection but also accelerated the natural process by the use of catalysts. When sunlight is used to break up toxic chemicalsmore » by direct absorption through the chemical surface, the process is called photolysis. If the objective is achieved by the use of catalysts, it is known as photocatalysis. Recent research has concentrated mainly on photocatalytic detoxification and disinfection.« less