A new semi-artificial electrode could convert light energy into other forms of energy in biosolar cells. The technique is based on the photosynthesis protein Photosystem I from cyanobacteria and can be coupled with an enzyme that used the converted light energy to produce hydrogen.
A research team from the Ruhr-Universität Bochum (RUB), together with colleagues from Lisbon, has produced a semi-artificial electrode that could convert light energy into other forms of energy in biosolar cells, announced a statement. The technique is based on the photosynthesis protein Photosystem I from cyanobacteria.
The group showed that they could couple their system with an enzyme that used the converted light energy to produce hydrogen.
Photosystem I is part of the photosynthesis machinery in cyanobacteria and plants. With the help of light energy, it can separate charges and thus generate high-energy electrons that can be transferred to other molecules, for example to protons for the production of hydrogen.
It usually occurs as a trimer, or three photosystems are always linked together. Since the trimers cannot be packed close together, holes appear in the monolayer, which can lead to short circuits. This impairs the performance of the system. It was precisely this problem that the scientists solved in the present work, explains the statement.
In the cyanobacterium Thermosynechococcus elongatus, photosystem I exists mainly as a trimer. Using a new extraction technique, the researchers were able to isolate additional monomers from the organism, creating a photosystem I monolayer on the electrode in which the monomers filled the holes between the trimers.
In this way, they reduced the short-circuit effects. The system achieved current densities twice as high as a system consisting only of trimers.
Photo: Flickr Creative Commons
