New power conversion layer for biosolar cells

• A study group from the Ruhr-Universitat Bochum (RUB), along with coworkers from Lisbon, has produced a semi-artificial electrode that could transform light energy right into various other forms of energy in biosolar cells.

The method is based upon the photosynthesis protein Photosystem I from cyanobacteria. The team revealed that they might combine their system with an enzyme that used the converted light power to create hydrogen. The results were released online ahead of time in October 2020 in the journal Angewandte Chemie.

For the work, the RUB group including Panpan Wang, Dr. Fangyuan Zhao, Dr. Julian Szczesny, Dr. Adrian Ruff, Dr. Felipe Conzuelo as well as Professor Wolfgang Schuhmann from the Center for Electrochemistry accepted the team consisting of Anna Frank, Professor Marc Nowaczyk and Professor Matthias Rogner from the Chair of Biochemistry of Plants in addition to coworkers from the Universidade Nova de Lisboa.

Short-circuit threat

Photosystem I is part of the photosynthesis machinery in cyanobacteria as well as plants. With the help of light energy, it can divide fees and also hence produce high-energy electrons that can be moved to various other molecules, for example to protons for the manufacturing of hydrogen.

In earlier work, the Bochum scientists had actually already utilized the light-collecting protein complex photosystem I to make electrodes for biosolar cells. For this purpose, they covered an electrode with a photosystem I monolayer. In such monolayers, the photosystems are not stacked on top of each other, yet lie side by side in the exact same aircraft.

Photosystem I, nevertheless, normally happens as a trimer, i.e. 3 photosystems are always linked together. Considering that the trimers can not be loaded close together, holes show up in the monolayer, which can bring about short circuits. This harms the performance of the system. It was exactly this trouble that the scientists addressed in today work.

Openings in the photosystem layer connected

In the cyanobacterium Thermosynechococcus elongatus, photosystem I exists mainly as a trimer. Making use of a new extraction strategy, the researchers had the ability to separate additionally monomers from the microorganism, producing a photosystem I monolayer on the electrode in which the monomers loaded the holes in between the trimers. In this way, they decreased the short-circuit impacts. The system achieved existing densities twice as high as a system being composed only of trimers.

To reveal what the strategy could be in concept used for, the scientists combined it to a hydrogenase enzyme that generated hydrogen using electrons provided by the photosystem. "Future work will certainly be directed toward a lot more reliable coupling in between the photosystem monolayer and the integrated biocatalysts to recognize sensible biosystems for solar power conversion," the authors preview in their publication.