Water Purification Chemical Uses Visible, Not UV, Light To Kill Bacteria

The World Health Organization estimates that around one sixth of the world lacks access to clean drinking water. Since those billion people are also the poorest people in the world, water purification techniques need to be cheap to help those most in need. Since it activates under plain visible light, this new water-purifying photocatalyst may help bring purer water to the world's neediest people.

Nitrogen-doped titanium oxide with a Palladium nanoparticle booster :  Shang, et al. University of Illinois at Urbana-Champaign, via Technology Review

Even more impressive, the palladium nanoparticles perpetuate the reaction so efficiently that the titanium oxide continues to purify the water even after the light is shut off. For countries with limited lighting infrastructure, or places prone to blackout, that greatly extends the purification power of the material.

[Technology Review]