"The path to the hydrogen economy is getting visibly brighter--literally. Nano-tubes that break apart water molecules to liberate hydrogen can now do so more efficiently and could soon use the optical spectrum of sunlight.
In dissociating water with sunlight, engineers have available three technologies: One is solar cells, which hold the record for water-splitting efficiency but are comparatively expensive. Another approach uses microorganisms, which are inexpensive but so far produce only minuscule amounts of hydrogen. The third option is photocatalysis, which relies on momentarily freed electrons in a semiconductor. Electrons that encounter water molecules replace the electrons in the bonds between hydrogen and oxygen. They thus break water apart and generate hydrogen gas. Photocatalysts are potentially less expensive than solar cells and produce more hydrogen than microorganisms...."
This article requires a subscription to Scientific American DIGITAL, or you can get the May 2006 issue of Scientific American.
Other links describing similar or related technologies:
- Tiny porphyrin tubes developed by Sandia may lead to new nanodevices news release from Sandia National Laboratories
- Hydrogenation of Single-walled Carbon Nanotubes uses nanotech to for hydrogen storage.
- Some background on Solar Hydrogen Production by Water-Splitting from CSIRO Industrial Physics
- and some uses of TiO2 photocatalysis
- The Nanotube Site
- Photocatalysis from Wikipedia
- Nanotube from Wikipedia
- Subscribe to Scientific American
No comments:
Post a Comment