* Astronomy

Scientists are hot on the trail of materials that use light to break down contaminants for environmental cleanup or split water for hydrogen fuel production. With a splash of UV light, titanium dioxide can do just that, but researchers would like to expand its repertoire to use visible light. Doping, or adding small amounts of another element, can change a metal oxide's characteristics. Pacific Northwest National Laboratory's Michael Henderson and colleagues added nitrogen to different forms of titanium dioxide known as anatase and rutile, and tested how well the nitrogen-doped metal oxides performed. The team measured how a test molecule decomposed as a stand-in for half of the water-splitting reaction -- the "oxidation" half of an oxidation-reduction reaction. While both metal oxides decomposed the test molecule under UV, only anatase could break it down in visible light, surprising the researchers. Henderson will talk about properties of doped anatase and rutile that might contribute to their contrasting skills.

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