Daniel Nocera and his colleagues from MIT debuted the first practical artificial leaf at the 2011 National Meeting of the American Chemical Society. Their version is cheap, effective and stable, overcoming in one swoop the three major problems of previous attempts to make artificial leaves.
The point of making artificial leaves (a.k.a. solar cells) is to generate cheap, clean energy. Nocera’s device does just that with a minimum of components: a thin wafer of silicon containing catalysts made of nickel and cobalt, a gallon of water, and sunlight. When those three components are combined, the catalysts in the wafer split the water into hydrogen and oxygen gases, which are then stored in fuel cells and ultimately used to generate electricity.
Compared to earlier incarnations of artificial leaves, beginning with the model John Turner (U.S. National Renewable Energy Laboratory) designed a decade ago, Nocera’s prototype shows real promise for widespread functionality. It is already ten times more efficient that natural leaves, a benchmark Nocera expects to be able to raise in the future. In addition, each slip of silicon can function continuously for over 45 hours. I assume they tested this feature with artificial light, rather than moving their sample around the Earth for two days.
You can watch an explanation below.