MIT's 'Artificial Leaf' Makes Fuel From Sunlight

New submitter nfn writes "MIT has published a new paper (abstract), along with a video of a working prototype, of what they're describing as an 'Artificial Leaf' that separates water into oxygen and hydrogen using cheap, non-exotic materials. 'The artificial leaf — a silicon solar cell with different catalytic materials bonded onto its two sides — needs no external wires or control circuits to operate. Simply placed in a container of water and exposed to sunlight, it quickly begins to generate streams of bubbles: oxygen bubbles from one side and hydrogen bubbles from the other. If placed in a container that has a barrier to separate the two sides, the two streams of bubbles can be collected and stored, and used later to deliver power: for example, by feeding them into a fuel cell that combines them once again into water while delivering an electric current.' No word on the arrival of 'Artificial Salads,' or when any of their other alchemy projects will bear artificial fruit."

Re:Now do it for CO2

[Attila Dimedici]

Actually, you bring up a decent point. Hydrogen is not very energy dense. This system would be great if we had a practical fusion reactor, but we don't. A much superior system would be one which takes sunlight, CO2 and water and produces a complex hydrocarbon that could then be used as fuel.

Re:Back in High School

[Dr_Barnowl]

The innovative bit is the cobalt catalyst. A lot of other designs use toxic electrolytes (as you mention) or expensive rare metal catalysts. This one has the advantage that all the raw materials are relatively cheap, for a solar panel design - no expensive platinum, gadolinium, etc.

Re:Losing Hydrogen

[wagnerrp]

Hydrogen is reactive. It will react with something on the way up through the atmosphere, that makes it sufficiently heavy to stick around. The problem with helium is that it is inert. It's perfectly content on its own, so it will simply float to the top of the atmosphere and exist in trace densities not economical to capture.