A research team from the Collaborative Research Center TRR/SFB 234 „CataLight“ at the Universities of Ulm and Jena has developed a novel material capable of storing solar energy and converting it into hydrogen on demand—even in the dark. Prof. Dr. B. Dietzek-Ivanšić, Scientific Director of our institute and member of the CataLight board, contributed to the study, which was published in the journal Nature Communications.

The system is based on a water-soluble, redox-active copolymer that efficiently stores energy from sunlight (with a charging efficiency of over 80%) and releases it as hydrogen when needed. The conversion is triggered by adding an acid and a catalyst, achieving an efficiency of around 72%—independent of current sunlight availability.

A key advantage of this approach is its reversibility. By simply adjusting the pH value, the system can be recharged and discharged multiple times without the need for complex material processing. This development effectively combines the functionalities of a solar cell and a battery at the molecular level.

The results open up new perspectives for scalable energy storage technologies and the on-demand provision of green hydrogen—for example, in energy-intensive industrial applications.

Further information:
M. Hartkorn, R. Kampes, F. Müller, L. Zedler, A. Edwards, Ph. Rohland, A. K. Mengele, S. Zechel, M. D. Hager, B. Dietzek-Ivanšić, M. Schmitt, J. Popp, U. S. Schubert, S. Rau
A water-soluble copolymer for storage and electron conversion in photocatalytic on-demand hydrogen evolution
Nature Communications 17 (2026) 1141, https://doi.org/10.1038/s41467-026-68342-2

For the full press release by Friedrich Schiller University Jena, please visit here.