Researchers at the Asian Institute of Technology (AIT) have successfully shown that visible light and zinc oxide nanorods can destroy bacterial water contamination. The combination of nanorods grown on glass substrates and solar energy is effective for killing both gram positive and gram negative bacteria. The findings open up immense possibilities for affordable and environmentally friendly water purification techniques. According to Professor Joydeep Dutta, director of the Center for Excellence in Nanotechnology at AIT, “Most studies so far either work on the use of ultraviolet light or involve a suspension of nanoparticles,” but the AIT group dispensed with both. Nanoparticle suspension methods usually require the removal of the nanoparticles after the water purification process. “Since ZnO has now been tested under solar light, instead of the traditionally used UV light, the potential for commercial applications is huge, particularly since the levels of zinc ions removed from the rods to the water are safe for human consumption,” added Dutta.
http://www.physorg.com/news/2011-05-exposing-zno-nanorods-visible-microbes.html