Design and Fabrication of Multicomponent Heterostructured Nanoparticles
Date of Award
Doctor of Philosophy (PhD)
Mathew M. Maye
Physical Sciences and Mathematics
The design and fabrication of sophisticated nanoparticle (NP) architectures are of increased desire as potential applications of these materials expand. In this dissertation research, I focus on designing and synthesizing heterostructured NPs, with complex morphology and tunable composition. Chapter 2 focuses on the synthesis of dumbbell NPs. I was able to make Au/Pd-Ag NPs, which are comprised of an Au core, and a Pd shell, where the addition of a third metal, Ag, yielded the epitaxial growth of Ag on one side of Au/Pd NP. Results suggest that with increased shell layers (n) of Ag, deposition occurs in a sub-monolayer fashion forming small-detached islands on the surface of the Au/Pd. By increasing n, these small islands eventually coalesce into one primary domain that resides asymmetrically with respect to the Au/Pd core. Chapter 3 uses the Au/Pd-Ag NPs as nano templates, where through the use of galvanic exchange, the composition of the heterostructure can be tuned to Au/Pd-Pt, Au/Pd-Au, or Au/Pd-Pd. More importantly, the finalized NPs all exhibited personalized morphology, of core/shell-hollow Au/Pd-Pt, core/shell-parachute Au/Pd-Au, and core/shell-uniform Au/Pd-Pd NPs. The respective systems were tested for catalytic activity, where Au/Pd-Pt nanoparticles exhibited superior catalytic activity towards methanol oxidation compared to its neighboring systems and a Pt/C standard. Finally, Chapter 5 discusses the work of catalytically active Au/Pt NPs, where modifications in the Pt morphology resulted in core/shell Au/Pt NPs or porous Au/Pt dumbbell NPs respectively. Catalytic comparison between the two systems demonstrated the higher catalytic activity of the porous Au/Pt dumbbell NP.
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Lutz, Patrick, "Design and Fabrication of Multicomponent Heterostructured Nanoparticles" (2015). Dissertations - ALL. 265.