Designing novel syntheses for controlled nanocrystal production
The focus of the group is the precise chemical synthesis of colloidal nanocrystals and their advanced structural characterization using X-ray scattering methods. To gain control over the size and shape of nanomaterials, we combine principles from organic chemistry, coordination chemistry, and crystallography. We stand for a rational approach with which we aim to fully understand the mechanism behind nanocrystal formation, in order to steer the outcome of the reaction. Our research is centered around the group 4 elements: titanium, zirconium and hafnium oxide, since their nanocrystals are technologically relevant but challenging to synthesize.
Elucidation and manipulation of nanocrystal surface chemistry
Most colloidal nanocrystals are not simply inorganic objects. Instead, they are organic-inorganic hybrid objects, with organic surfactants adsorbed to the surface of the inorganic core. We are specialized in studying this peculiar interface, which is one of the most important aspects for nanocrystal applications. We use advanced NMR (nuclear magnetic resonance) techniques to identify the surface-adsorbed species and to assess the thermodynamics of binding. By combining nanocrystal surface analysis and nanocrystal core analysis, we strive to uncover the total structure of nanocrystals.
Novel memory devices based on nanocrystals
For further miniaturizing of computer chips beyond Moore’s Law, standard complementary metal oxide semiconductor (CMOS) circuits need to be replaced with novel technology that switches faster and has lower power consumption. In this regard, threshold memristors are being intensely researched. Such materials switch between a high resistance and a low resistance state by applying voltage. In collaboration with the Nonnenmann group of the University of Massachusetts Amherst (USA), we deposit colloidal metal oxide nanocrystals and evaluate their performance as memristors.
Oxo clusters as atomically defined building blocks
Metal oxo clusters are atomically defined structures, in between metal complexes and nanocrystals. They are used as the inorganic nodes in metal organic frameworks (MOFS) or a building blocks in 3D printing. Despite the very simple synthetic procedures, the formation mechanism is still largely unknown. In our lab, we develop purification and characterization procedures and apply classical physical chemistry approached to elucidating the mechanism of cluster formation.