The artificial leaf, a device that can harness sunlight to split water into hydrogen and oxygen without needing any external connections, have been developed by a team led by MIT professor Daniel Nocera. Like living leaves, they can convert the energy of sunlight directly into storable chemical form which can be used later as an energy source.
The device is in fact a silicon solar cell with different catalytic materials bonded onto its two sides; needing 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.
Nocera sees a future in which individual homes could be equipped with solar-collection systems based on this principle: Panels on the roof could use sunlight to produce hydrogen and oxygen that would be stored in tanks, and then fed to a fuel cell whenever electricity is needed. Such systems, Nocera hopes, could be made simple and inexpensive enough so that they could be widely adopted throughout the world, including many areas that do not presently have access to reliable sources of electricity.
So next time you mindlessly pluck leaves off a plant, in anger or in disgust or in romance, just think about how much energy you will be wasting in the process! via.