Artificial photosynthesis, the technology of converting sunlight into liquid fuels, would be the greenest of green technology if it can be done economically and on a large scale. Plants store energy derived from the sun in the form of chemical bonds created by photosynthesis. We would like to do the same thing in the laboratory.
A research group at Lawrence Berkeley National Laboratory is reporting promising results with a new technique to produce hydrogen fuel from sunlight. They have developed a new photocathode material that is capable of using the absorption of visible light to produce energetic electrons in target hydrogen molecules. This is a key first step toward the creation of bionic leaves – essentially devices that produce energy-dense fuels from nothing more than sunlight, water, and carbon dioxide.
Solar energy systems only work when the sun is shining. As a result, we can only depend on them if we have a way of storing the energy they produce for use at night. We can use batteries to store the electricity generated by photovoltaic systems and we can use molten salts to store the heat generated by solar thermal systems. But nature’s mechanism of turning sunlight into the chemical bonds of fuel is a more direct approach.
There are multiple technical problems to solve before bionic leaves become a practical source of energy including increasing the efficiency of absorbing solar energy in the photocathodes. But with progress like the recent work at Berkeley, the prospects for creating a technology that uses the sun the way plants do are growing all the time.
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Promising news for producing fuels through artificial photosynthesis
Photo, taken June 6, 2006, courtesy of Angelo DeSantos via Flickr.
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Earth Wise is a production of WAMC Northeast Public Radio. Support for Earth Wise comes from the Cary Institute of Ecosystem Studies in Millbrook, NY.