Popeye loved spinach because it made him strong, but what else is spinach good for? Scientists have discovered a cell in spinach that can use sunlight to produce electricity and hydrogen.
Researchers from the Technion-Israel Institute of Technology have developed a bio-photo-electro-chemical (BPEC) cell that produces electricity and hydrogen from water using sunlight. They were able to do this by using a simple membrane extract from spinach leaves. Water is the raw material of the device. It produces electric current, hydrogen and oxygen. These findings were published in the August 23 online issue of Nature Communications.
This unique combination of a man-made BPEC cell and plant membranes that are able to absorb sunlight and convert it into a flow of electrons highly efficiently, paves the way for the development of new technologies for the creation of clean fuels from renewable sources: water and solar energy.
Researchers based the BPEC cell on the naturally occurring process of photosynthesis in plants. In this process, light drives electrons that produce storable chemical energetic molecules that are the fuel of all cells in the animal and plant world.
The researchers added an iron-based compound to the solution in order to harness an electric current from photosynthesis. This compound mediates the transfer of electrons from the biological membranes to the electrical circuit. This enables the creation of an electric current in the cell.
This electrical current can even be channeled to form hydrogen gas through the addition of electric power from a small photovoltaic cell that absorbs the excess light. Because of this, solar energy can be converted into chemical energy that is stored as hydrogen gas formed inside the BPEC cell. By burning the hydrogen, this energy can be converted into electricity and heat.
This is much like hydrocarbon fuels, without harmful emissions. Because this product produces hydrogen combustion, it creates a closed cycle that is sustainable. Hydrogen combustion creates clean water, therefore the cycle begins with water and ends with water. This allows the conversion and storage of solar energy in hydrogen gas, which could be a clean and sustainable substitute for hydrocarbon fuel.
The study was conducted by doctoral students Roy I. Pinhassi, Dan Kallmann and Gadiel Saoer, under the guidence of Prof. Noam Adir of the Schulich Faculty of Chemistry, Prof. Gadi Schuster of the Faculty of Biology and Prof. Avner Rothschild of the Faculty of Material Science and Engineering.