Freigeist Fellowship for Tristan Petit
Dr. Tristan Petit will broaden his research on nanocarbon materials with the Freigeist Fellowship. © HZB
For his project on nanodiamond materials and nanocarbon, Dr. Tristan Petit has been awarded a Freigeist Fellowship from the VolkswagenStiftung. The grant covers a five-year period and will enable him to establish his own research team. The VolkswagenStiftung is funding with these prestigious fellowships outstanding postdocs planning original research that transcends the bounds of their own field.
Following his doctoral studies, Dr. Tristan Petit joined the HZB team of Prof. Emad Aziz supported by a post-doctoral stipend from the Alexander von Humboldt Foundation. He had already investigated surface modification of nanodiamonds while exploring their potential for biomedical applications during his doctoral research at the Diamond Sensors Laboratory (CEA) in Gif sur Yvette, France. Petit has since expanded his research interests. This is because nanodiamond materials can also exhibit catalytic effects, in particular when irradiated by sunlight. One dream is to develop synthetic nanodiamond materials for manufacturing solar fuels like methane using sunlight and carbon dioxide, thereby storing solar energy chemically. Aziz and Petit are now working on this project under the European DIACAT research programme.
As a Freigeist Fellow, Petit will investigate how nanocarbon materials in aqueous solutions interact with their environment. These interactions have hardly been studied so far, but they are essential for developing new applications and being better able to assess risks.
It is very difficult to study nanocarbon materials in aqueous solutions experimentally, though. Spectrographic methods using X-ray light can provide information about the electrochemical and photochemical processes. Petit relies on specialised setups for this such as LiXEdrom at BESSY II that were developed at HZB specifically for these kinds of experiments. He intends to use infrared spectroscopy to determine the configuration of water molecules surrounding the nanoparticles. Petit also plans to carry out sequential laser-based pump-probe measurements in order to observe ultrafast electronic processes in the nanoparticles. The methods have already proven themselves in nanocarbon solid-state experiments, but their utilisation in studying nanocarbon in liquids is new, however.
“The Freigeist Fellowship makes it possible for me to research these problems comprehensively. Once we better understand the complex interactions between nanocarbon particles in an aqueous environment, we will be able to develop a new generation of carbon-based nanomaterials for different applications – from photocatalysis of solar fuels to medical applications”, says Petit. The Freigeist Fellowship is accompanied by funding of 805,000 EUR, of which 375,000 EUR is provided by HZB in-house resources and 430,000 EUR by the VolkswagenStiftung.
As a result, there are now two Freigeist Fellows on Aziz’ team. Dr. Annika Bande also received a Freigeist Fellowship last year and has since been working at the HZB Institute for Methods of Material Development headed by Aziz.
Further information on the Freigeist Fellowships: www.volkswagenstiftung.de/freigeist-fellowships.
- What Zinc concentration in teeth revealsTeeth are composites of mineral and protein, with a bulk of bony dentin that is highly porous. This structure is allows teeth to be both strong and sensitive. Besides calcium and phosphate, teeth contain trace elements such as zinc. Using complementary microscopy imaging techniques, a team from Charité Berlin, TU Berlin and HZB has quantified the distribution of natural zinc along and across teeth in 3 dimensions. The team found that, as porosity in dentine increases towards the pulp, zinc concentration increases 5~10 fold. These results help to understand the influence of widely-used zinc-containing biomaterials (e.g. filling) and could inspire improvements in dental medicine.
- Fascinating archaeological find becomes a source of knowledgeThe Bavarian State Office for the Preservation of Historical Monuments (BLfD) has sent a rare artefact from the Middle Bronze Age to Berlin for examination using cutting-edge, non-destructive methods. It is a 3,400-year-old bronze sword, unearthed during archaeological excavations in Nördlingen, Swabia, in 2023. Experts have been able to determine how the hilt and blade are connected, as well as how the rare and well-preserved decorations on the pommel were made. This has provided valuable insight into the craft techniques employed in southern Germany during the Bronze Age. The BLfD used 3D computed tomography and X-ray diffraction to analyse internal stresses at the Helmholtz-Zentrum Berlin (HZB), as well as X-ray fluorescence spectroscopy at a BESSY II beamline supervised by the Bundesanstalt für Materialforschung und -prüfung (BAM).
- Element cobalt exhibits surprising propertiesThe element cobalt is considered a typical ferromagnet with no further secrets. However, an international team led by HZB researcher Dr. Jaime Sánchez-Barriga has now uncovered complex topological features in its electronic structure. Spin-resolved measurements of the band structure (spin-ARPES) at BESSY II revealed entangled energy bands that cross each other along extended paths in specific crystallographic directions, even at room temperature. As a result, cobalt can be considered as a highly tunable and unexpectedly rich topological platform, opening new perspectives for exploiting magnetic topological states in future information technologies.