Scientists have now been able to replicate a critical step of photosynthesis using entirely artificial molecules. This research, just published in the journal Angewandte Chemie, brings us closer to being able to easily generate energy from sunlight using artificial photosynthesis.
In natural photosynthesis, plants are able to store electric charges for a brief period of time after absorbing sunlight. These charges are then used to power other steps of photosynthesis, such as the reduction of carbon dioxide. In carbon dioxide reduction, CO2 from the atmosphere is converted into carbohydrates, sugars that are stored and later used as energy. Charge accumulation is also used in other photosynthetic processes, including water oxidation. In the past, researchers had been unable to replicate these natural processes that utilized charge accumulation.
The researchers used a laser to excite artificial molecules they had created earlier. They were able to store two negative charges for 870 nanoseconds, enough time for generating energy through artificial photosynthesis. Charge accumulations had been done before by using sacrificial reagents, chemicals that need to be used up in the reaction. These chemicals often took a lot of energy to produce, making their use unsustainable. In this experiment, the researchers were able to accumulate and store charges without using any sacrificial reagents, making the technique more attractive for generating sustainable energy.
Artificial photosynthesis represents an exciting step towards generating “green” energy from natural sunlight. Now, the process has been made more practical using the techniques invented by researchers. Researchers from the University of Basel and the University of Zurich, some of them having worked on this paper, already have studies planned to build on this new knowledge. Scientists intend to investigate possible techniques for using this charge accumulation technique in order to generate fuel. In the future, humans will need to turn to more sustainable, environmentally friendly energy sources. Scientists are hopeful that artificial photosynthesis systems will prove to be a reliable form of green energy.
Orazietti, M. Kuss-Petermann, P. Hamm, O. S. Wenger. Light-Driven Electron Accumulation in a Molecular Pentad. Angewandte Chemie (2016).