Pretty impressive. Surprise there would be that much cost with components listed. Zinc, Cobalt etc are all pretty cheap. I would look for some goliath corporation like GE to buy this technology up to stop it from being developed out.
Pretty cool stuff but just like Solyndra, it apparently can't compete with cheap Chinese solar panels. 'Artificial leaf' faces economic hurdle : Nature News
Why would GE not want it developed. They may want to sell it on their own, and profit. Its companies like BP that and Brightsource that lose out if this is developed. That said photovoltaic to grid seems much less expensive than artificial leaf + water to hydrogen + oxygen to fuel cell. I can see some modification working well in a combined power plant, desalinization plant if they can get the water spliters to work well with sea water.
I must be getting old. My high school science taught me that plants do photo synthesis ... turned water/sun and CARBON DIOXIDE into carbs/sugars ... and that THAT's the stuff that got made, and got stored in the plants during the night. Maybe that's why I only got a 'C' ... I should'a been thinking plants used oxygen to make hydrogen. Maybe I should keep open flames away from my nectarine and apple trees, with all that hydrogen going on.
I shook my head too at the artificial leaf moniker. Guess someone thought since both involve compound splitting. But just refreshed my memory on the process, and the light cycle does split water. The hydrogen for the sugars has to come from some where.
When you get into the mechanisms, there are protons separated from oxygen by the chlorophyll and light in the stoma protons are hydrogen ions without their electrons. These are transported to the lumen and other reactions take place. IIRC ferrodoxin, NADP+, FAD, are involved in the mechanism. In nature if co2 levels are higher a plant can produce smaller and/or fewer stoma, which means it needs less water (more drought resistant). In an artificial leaf you would simply collect the hydrogen and oxygen, instead of synthesizing carbohydrates with the H and carbon dioxide.
