With this award, the Macromolecular, Supramolecular and Nanochemistry program in the Division of Chemistry is funding Professor Petra Reinke at the University of Virginia to develop novel, ultrasmall catalyst particles that consist of carbon (carbides) chemically bound to a metal. These particles, with diameters of less then a few billionths of a meter, havea wide range of potential applications, from catalysis, where carbide-based particles can substitute for expensive noble metals, to molecular electronics. The project addresses two challenges, which are critical bottlenecks for the use of carbide-based nanoparticles: First, the synthesis of stable carbide-based nanoparticles with a narrow size distribution, which can be adapted to maximize performance, and second, understanding the impact of geometric and electronic structure on chemical reactivity. Outreach activities, and the development of a web-based, student-designed nanotechnology resources are integrated with the research program.
Nanoparticle curvature, as a control parameter for molecule adsorption geometry, has the potential to function as a powerful tool in driving bottom-up assembly. The present proposal targets the size regime where molecule size becomes comparable to the diameter of a metallic or semiconducting nanoparticle on which it is adsorbed. The proposed work targets two areas, first, the synthesis of stable ultra-small nanoparticles (nanospheres) as model systems, and, second, the study of molecule adsorption. The nanospheres are formed by a solid-state reaction between fullerenes, which serve as the carbon scaffold, and a metal substrate. The mechanism of nanosphere formation will be studied to control composition, bonding and surface structure. The mechanisms of nanosphere synthesis, and the adsorption of coronene on these nanospheres will be studied mainly with scanning tunneling microscopy and spectroscopy. Synchrotron-based photoelectron spectroscopy will be applied to elucidate bonding, and adsorption-induced changes in the molecule. The experimental work will be integrated with (i) statistical image analysis, (ii) simulation of tip convolution for curved surfaces, and (iii) simulation of metal-molecule interaction and nanosphere formation with DFT (density functional methods).