Not all titanium dioxide is equal when it comes to splitting water with visible light
Michael Henderson
IIC researchers presented at this year's American Chemical Society 2009 Spring Meeting
(March 2009)
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.
This work was supported by the Department of Energy's Chemical Sciences Division of Basic Energy Sciences, part of the Office of Science.
For more information, see Photochemical activities of nitrogen doped rutile and anatase surfaces.
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