Saturday, November 23, 2013

Copper promises cheaper, sturdier fuel cells

The copper nanowire films consist of networks of microscopic metal rods, the properties and applications of which Wiley's lab has studied for years. The nanowires provide a high surface area for catalyzing chemistry, and Wiley's team experimented with coating them in either cobalt or nickel -- metals that serve as the actual chemical catalyst. Even with a coat of cobalt or nickel, the nanowire films allow nearly seven times more sunlight to pass through than ITO. The films are also flexible, leading Wiley to imagine the completed fuel cells one day being attached to backpacks or cars.
In the meantime, engineering and chemistry challenges remain. The nanowire films carry out only one half of the water-splitting equation, a process called water oxidation. The other half of the reaction involves using the electrons obtained from water oxidation to reduce water to hydrogen. Wiley's team expects to publish their work on this process in the coming year.
"A lot of groups are working on putting together complete devices to generate fuels from sunlight," he said, but "the efficiencies and costs of these systems have to be improved for them to get to commercial [production]."
Wiley noted that solar energy production is just one application of the copper nanowire films they study. The nanowires also show promise for use in flexible touch screens, organic LED (or OLED) lights and smart glass.

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