Scientists from the Massachusetts Institute of Technology have finally developed the world's first practical artificial leaf that can split water into hydrogen and oxygen using sunlight at an economical cost, thereby achieving one of the milestones in the drive for sustainable energy.
They have described an advanced solar cell the size of a poker card that mimics the process, called photosynthesis, that green plants use to convert sunlight and water into energy.
"A practical artificial leaf has been one of the Holy Grails of science for decades. We believe we have done it," said Daniel Nocera, who led the research team.
The new discovery 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. One can envision villages in India and Africa not long from now purchasing an affordable basic power system based on this technology," said Nocera.
About the shape of a poker card but thinner, the device is fashioned from silicon, electronics and catalysts, substances that accelerate chemical reactions that otherwise would not occur, or would run slowly. Placed in a single gallon of water in a bright sunlight, the device could produce enough electricity to supply a house in a developing country with electricity for a day, said Nocera.
It does so by splitting water into its two components, hydrogen and oxygen.
The hydrogen and oxygen gases would be stored in a fuel cell, which uses those two materials to produce electricity, located either on top of the house or beside it.
The new leaf is made of inexpensive materials that are widely available, works under simple conditions and is highly stable. In laboratory studies, Nocera showed that an artificial leaf prototype could operate continuously for at least 45 hours without a drop in activity.
Right now, Nocera's leaf is about 10 times more efficient at carrying out photosynthesis than a natural leaf.
The finding was recently presented at the 241st National Meeting of the American Chemical Society.