Since in the course of evolution, bacteria, algae and various plants developed a very efficient mechanism for producing energy from solar radiation - the process of photosynthesis - one of the trends in the production of renewable energies today is the development of bio-solar cells based on this process
Researchers from the Technion and their colleagues in Germany present a significant improvement in the efficiency of biosolar cells that produce electricity and fuel using solar energy. The researchers are Dr. Dvir Harris and Prof. Noam Adir from the Schulich Faculty of Chemistry at the Technion and their colleagues Prof. Mark Novachik and Dr. Polka Hartman from RUB (Ruhr-Universität Bochum). The article was published on the cover page of the Journal of Materials Chemistry A.
The development of renewable and sustainable energy sources has accelerated in recent decades, following the recognition of the harms of using fossil fuels such as coal and oil. However, similar to the production of mineral fuels, the production of renewable fuels such as hydrogen requires a large energy investment, so the ambition is to use the inexhaustible source of energy - the sun.
Since in the course of evolution, bacteria, algae and various plants developed a very efficient mechanism for producing energy from solar radiation - the process of photosynthesis - one of the trends in the production of renewable energies today is the development of bio-solar cells based on this process. These cells incorporate natural systems for energy conversion, and one of them is PSII - a large protein cluster that breaks down water into electrons, protons and oxygen (as a by-product) using solar energy.
The disadvantage of the PSII system is that it knows how to absorb and utilize a narrow field (spectrum) of solar radiation, and therefore does not utilize the full potential of this resource - for example, green light, which constitutes about half of the visible light spectrum. To overcome this, the Technion researchers attached PSII to the phycobilisome - a unique protein complex found in cyanobacteria, which is a common marine organism that produces its energy through photosynthesis. The phycobilisome has developed in a way that allows the cyanobacteria to also harvest the radiation that the PSII system does not know how to absorb, and transfer it to PSII for further use. This combination of the two systems has not yet been reproduced in artificial systems.
Now, for the first time, Technion and RUB researchers have combined the PSII and the picobilisome in a single engineering system that is a photoanode - a light-sensitive electrode. Furthermore, they experimentally demonstrated the efficiency of the photoanode in converting solar radiation, along the entire spectrum of visible light, into electrical energy. According to Prof. Adir, "We intend to continue developing the system in order to extend the life span of its biological components and the utilization of energy. In our estimation, PSII-picobilisome photoanodes may become an accepted means of energy production and accelerate the use of renewable energy."
The research was funded by the Israel-Germany Cooperation Fund on Nano-Opto-Bioelectronics within the Israel National Science Foundation and the German Science Foundation (DFG).
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