Researchers at Linkoping University (LiU), Sweden, have developed a molecule that absorbs energy from sunlight and stores it in chemical bonds. The possible long-term use of the molecule is to efficiently capture solar energy and store it for later use. The study is published in the Journal of the American Chemical Society (JACS).
The Earth receives from the Sun many times more energy than humans can use. This energy is absorbed by objects of solar energy, such as panels, but one of the tasks of solar energy is to store it efficiently. It is important that energy is available when the sun is not shining. This led scientists at Linkoping University to investigate the possibility of capturing and storing solar energy in a new molecule.
Our molecule can take two different forms: a parental form, which can absorb energy from sunlight, and an alternative form, in which the structure of the parental form has been changed and made much more energy-intensive while remaining stable. This makes it “can efficiently store the energy of sunlight in a molecule.
The molecule belongs to a group known as molecular photoswitches. They are always available in two different forms, isomers, which differ in their chemical structure. These two forms have different properties, and in the case of the molecule developed by the LiU researchers, the difference lies in the energy content. The chemical structures of all photoswitches are influenced by the energy of light. This means that the structure and therefore the properties of the photoswitch can be changed by lighting it. One of the possible fields of application for photoswitches is molecular electronics, in which the two forms of the molecule have different electrical conductivity. Another area is photopharmacology, in which one form of the molecule is pharmacologically active and can bind to a specific target protein in the body, while the other is inactive.
Most chemical reactions begin in a state where a molecule is high in energy and then goes on to a low energy molecule. In the new study, the researchers did the opposite – a low-energy molecule becomes a high-energy molecule. “We expect it to be difficult, but we have shown that such a reaction can occur both quickly and efficiently,” the scientists conclude.
Researchers will now explore how stored energy can be best released from the energy-rich form of the molecule.