Most Important News of the Decade? Artificial Leaf Announced
March 29, 2011
Daniel Nocera of MIT and his team announced this week the latest development in their quest for the holy grail of solar energy.
A research team from the Massachusetts Institute of Technology (MIT) led by Dr. Daniel Nocera, Ph.D., claims to have made a drastic discovery in the world of sustainable energy by developing the first “practical” artificial leaf. These leaves are actually advanced solar cells that mimic photosynthesis, the process by which their real-life counterparts convert sunlight and water into energy. According Nocera, the leaves, although small in size, “”could produce enough electricity to supply a house in a developing country with electricity for a day.”
The team introduced their creation this past weekend at the 241st National Meeting of the American Chemical Society in Anaheim, California, but the concept of an artificial leaf is not entirely new. In fact, John Turner of the U.S. Renewable Energy Laboratory in Boulder, Colorado created the first artificial leaf about a decade ago. However, the biggest drawback of Turner’s leaf was that it required rare, expensive metals. Moreover, it was highly unstable, with a lifespan of about one day.
Nocera’s leaf, on the other hand, is about the size of a poker playing card and fashioned from “inexpensive materials that are widely available”, such as silicon, nickel, cobalt, and some electronics. It’ll also require about a gallon of water in the process. Nocera says that the leaf is able to work under “simple conditions” and is highly stable. In laboratory research, he showed that his team’s leaf worked continuously for “at least 45 hours” without a drop in activity.
“Nature is powered by photosynthesis, and I think that the future world will be powered by photosynthesis as well in the form of this artificial leaf,” said Nocera
Nocera, who is with the Massachusetts Institute of Technology, points out that the “artificial leaf” is not a new concept. The first artificial leaf was developed more than a decade ago by John Turner of the U.S. National Renewable Energy Laboratory in Boulder, Colorado. Although highly efficient at carrying out photosynthesis, Turner’s device was impractical for wider use, as it was composed of rare, expensive metals and was highly unstable — with a lifespan of barely one day.
Nocera’s new leaf overcomes these problems. It is made of inexpensive materials that are widely available, works under simple conditions and is highly stable. In laboratory studies, he showed that an artificial leaf prototype could operate continuously for at least 45 hours without a drop in activity.
The key to this breakthrough is Nocera’s recent discovery of several powerful new, inexpensive catalysts, made of nickel and cobalt, that are capable of efficiently splitting water into its two components, hydrogen and oxygen, under simple conditions. Right now, Nocera’s leaf is about 10 times more efficient at carrying out photosynthesis than a natural leaf. However, he is optimistic that he can boost the efficiency of the artificial leaf much higher in the future.
“Nature is powered by photosynthesis, and I think that the future world will be powered by photosynthesis as well in the form of this artificial leaf,” said Nocera, a chemist at Massachusetts Institute of Technology in Cambridge, Mass.
According to Nocera, the device would require about a gallon of water and exposure to bright sunlight to supply a household in a developing country with one day of electricity. The energy is created by splitting water into hydrogen and oxygen. The hydrogen and oxygen gases would be stored in a fuel cell, which would be used as a power source.
“A practical artificial leaf has been one of the Holy Grails of science for decades,” said Nocera. “We believe we have done it. The artificial leaf shows particular promise as an inexpensive source of electricity for homes of the poor in developing countries. Our goal is to make each home its own power station,” he said. “One can envision villages in India and Africa not long from now purchasing an affordable basic power system based on this technology.”
In an older video, Nocera describes the research: