

Re-inventing the Leaf: Artificial Photosynthesis to Create Clean Fuel - indiejade
http://www.scientificamerican.com/article.cfm?id=reinventing-the-leaf

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indiejade
P.S. The print-friendly link:

[http://www.scientificamerican.com/article.cfm?id=reinventing...](http://www.scientificamerican.com/article.cfm?id=reinventing-
the-leaf&print=true)

 _In photosynthesis, green leaves use the energy in sunlight to rearrange the
chemical bonds of water and carbon dioxide, producing and storing fuel in the
form of sugars. “We want to make something as close to a leaf as possible,”
Lewis says, meaning devices that work as simply, albeit producing a different
chemical output. The artificial leaf Lewis is designing requires two principal
elements: a collector that converts solar energy (photons) into electrical
energy (electrons) and an electrolyzer that uses the electron energy to split
water into oxygen and hydrogen. A catalyst—a chemical or metal—is added to
help achieve the splitting. Existing photovoltaic cells already create
electricity from sunlight, and electrolyzers are used in various commercial
processes, so the trick is marrying the two into cheap, efficient solar films.

<snip>

The problem is that commercial solar cells contain expensive silicon crystals.
And electrolyzers are packed with the noble metal platinum, to date the best
material for catalyzing the water-splitting reaction, but it costs $1,500 an
ounce._

So the major hurdle for the electrolyzer component is platinum, because it is
rare and expensive. But solar / photovoltaic-derived energy is the future.
Ergo: investments in platinum could be very lucrative.

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borneogamer
You realize they can use other materials as catalyst beside platinum as
electrolyzers?

