Popeye, the famous cartoon character, sang “I’m strong to the finish ’cause I eats me spinach, I’m Popeye the sailor man.”
Spinach, which contains iron, is indeed known for its nutritional value; but who knew it can also generate electricity? Well, a group of Israeli researchers has come up with a cell that uses sunlight to generate power from spinach leaves extract.
Using a simple membrane extract from spinach leaves, 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.
A source of renewable energy
The raw material of the device is water, and its products are electric current, hydrogen and oxygen. “The unique combination of a man-made BPEC cell and plant membranes, which 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,” according to a Technion statement.
The BPEC cell developed by the researchers is based on the naturally occurring process of photosynthesis in plants, in which light drives electrons that produce storable chemical energetic molecules, which are the fuels of all cells in the animal and plant worlds.
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In order to utilize photosynthesis for producing electric current, the researchers added an iron-based compound to the solution. This compound mediates the transfer of electrons from the biological membranes to the electrical circuit, enabling the creation of an electric current in the cell.
“A closed cycle that begins with water and ends with water”
The electrical current can also be channeled to form hydrogen gas through the addition of electric power from a small photovoltaic cell that absorbs the excess light. This makes possible the conversion of solar energy into chemical energy that is stored as hydrogen gas formed inside the BPEC cell. This energy can be converted when necessary into heat and electricity by burning the hydrogen, in the same way hydrocarbon fuels are used.
However, unlike the combustion of hydrocarbon fuels – which emit greenhouse gases (carbon dioxide) into the atmosphere and pollute the environment – the product of hydrogen combustion is clean water. Therefore, “this is a closed cycle that begins with water and ends with water, allowing the conversion and storage of solar energy in hydrogen gas, which could be a clean and sustainable substitute for hydrocarbon fuel,” according to the researchers.
The study was conducted by doctoral students Roy Pinhassi, Dan Kallmann and Gadiel Saper, under the guidance of Prof. Noam Adir, Prof. Gadi Schuster and Prof. Avner Rothschild. It was recently published in the scientific journal Nature Communications.
Photos: Technion, jean pierre gallot