Two Freigeist Fellows interweave their research at HZB
Fabian Weber (right) is investigating the dynamics of electron processes within graphene-oxide quantum dots as a member of the team headed by Dr. Annika Bande (left). Quantum dots like these as catalysts could help make solar water splitting more efficient. Using Weber’s theoretical model, a much greater amount of information can be obtained from the empirical data gathered by the group headed by Dr. Tristan Petit. © HZB
Initial calculations show how the electron density changes over a graphene oxide nanoparticle in solution. The electron density is below average in the areas shown in red, while it is above average in the blue areas. The graphene particle is made of carbon atoms (black) that bind in some places to the oxygen (red) , or in some to the hydrogen (white). © Fabian Weber
Two Freigeist Fellows are conducting research at the HZB Institute for Methods of Material Development through support received from the Volkswagen Foundation. Theoretical chemist Dr. Annika Bande is modelling fast electron processes, while Dr. Tristan Petit is investigating carbon nanoparticles. Annika Bande has now been awarded an ancillary grant of an additional 150,000 Euros from the Volkswagen Foundation to fund another doctoral student position for three years. The doctoral research will connect the two Freigeist research projects with one another.
Doctoral student Fabian Weber is working in Bande’s theory group and will be carrying out electron transfer calculations in a material system being investigated by Petit and his team. “We are concentrating on a special class of what are known as quantum dots, made of graphene oxide nanoparticles”, explains Weber. The group headed by Petit will be analysing nano-graphene oxide using various spectroscopic methods.
Catalyst for solar hydrogen
This is because graphene-oxide nanoparticles are good catalysts, as well for splitting water using solar energy and generating hydrogen. Hydrogen is a versatile energy medium that can be utilised as fuel or to generate environmentally friendly electric power in a fuel cell.
Understanding the system
With the help of theoretical modelling, the empirical data obtained on nanoparticles of graphene oxides can yield considerably more information and also new insights into the ultrafast dynamics of hydrogen bonding. “We start with existing theories and see how we can use them to model exactly what happens with the transfer of electrons during a catalytic reaction”, explains Annika Bande. “We are able to compare our ideas directly with the empirical results in this research project and really come to better understand the system. In addition, the topic is extremely important – not just for purposes of pure research, but also for ensuring society’s energy supply.”
- Ernst Eckhard Koch Prize and Innovation Award on Synchrotron Radiation 2025At the 27th BESSY@HZB User Meeting, the Friends of HZB honoured the dissertation of Dr Enggar Pramanto Wibowo (Friedrich-Alexander University Erlangen-Nuremberg). The Innovation Award on Synchrotron Radiation 2025 went to Prof. Tim Salditt (Georg-August-University Göttingen) and Professors Danny D. Jonigk and Maximilian Ackermann (both, University Hospital of RWTH Aachen University).
- Bright prospects for tin perovskite solar cellsPerovskite solar cells are widely regarded as the next generation photovoltaic technology. However, they are not yet stable enough in the long term for widespread commercial use. One reason for this is migrating ions, which cause degradation of the semiconducting material over time. A team from HZB and the University of Potsdam has now investigated the ion density in four different, widely used perovskite compounds and discovered significant differences. Tin perovskite semiconductors produced with an alternative solvent had a particular low ion density — only one tenth that of lead perovskite semiconductors. This suggests that tin-based perovskites could be used to make solar cells that are not only really environmentally friendly but also very stable.
- Synchrotron radiation sources: toolboxes for quantum technologiesSynchrotron radiation sources generate highly brilliant light pulses, ranging from infrared to hard X-rays, which can be used to gain deep insights into complex materials. An international team has now published an overview on synchrotron methods for the further development of quantum materials and technologies in the journal Advanced Functional Materials: Using concrete examples, they show how these unique tools can help to unlock the potential of quantum technologies such as quantum computing, overcome production barriers and pave the way for future breakthroughs.