@unpublished{pittir30831, month = {July}, title = {Mechanisms of Metal Deposition on Gold Nanoparticle Substrates}, author = {Patrick Straney}, year = {2017}, keywords = {Nanoparticle, Nanotechnology, Surface Chemistry, Gold, Platinum}, url = {http://d-scholarship-dev.library.pitt.edu/30831/}, abstract = {Understanding the chemical mechanisms underlying multimetallic nanoparticle nucleation and growth is crucial for translating the unique properties that emerge on the nanoscale. However, limited knowledge of nanoscale nucleation and growth processes challenges our ability to synthesize and characterize these materials in a robust and reproducible fashion. This dissertation identifies and describes synthetic mechanisms that direct metal on metal growth processes for gold nanoparticle substrates with unprecedented chemical detail. In Chapter 1, the dissertation is introduced with a background on the processes that influence multimetallic nanoparticle formation in relation to classic thin film growth modes. Specifically, the chapter focuses on metal-on-metal nucleation and growth mechanisms and highlights current advances in the synthesis of multimetallic nanoparticles through island-type deposition pathways. Chapter 2 demonstrates homogeneous nucleation as a robust, scalable, and sustainable method to synthesize anisotropic Au nanorods and nanoprisms relative to traditional seed mediated strategies. With effective methods to synthesize anisotropic Au nanoparticles, Chapter 3 builds on these results and uses Au nanoparticles as substrates for secondary metal deposition and multimetallic nanoparticle formation. Specifically, Chapter 3 describes pathways of Pt island deposition and identifies chemical mechanisms impacting surface chemistry vs. redox mediated growth pathways. Building on these results, Chapter 4 identifies the use of metal-ligand surface chemistry to promote edge, facet, or vertex selective nucleation of Pd, Pt, and Au nanoparticles on anisotropic Au nanoparticle substrates. Finally, Chapter 5 describes the deposition of Cu on Au nanoprisms and the challenges of incorporating 3d transitions metals into traditional noble metal syntheses. Together, these chapters demonstrate metal-ligand surface chemistry as a robust and efficient means of influencing the morphology, composition, and properties of multimetallic transition metal nanostructures.} }