title: Decoupling mechanisms of platinum deposition on colloidal gold nanoparticle substrates.
abstract: Nanoscale platinum materials are essential components in many technologies, including catalytic converters and fuel cells. Combining Pt with other metals can enhance its performance and/or decrease the cost of the technology, and a wide range of strategies have been developed to capitalize on these advantages. However, wet chemical synthesis of Pt-containing nanoparticles (NPs) is challenging due to the diverse metal segregation and metal-metal redox processes possible under closely related experimental conditions. Here, we elucidate the relationship between Pt(IV) speciation and the formation of well-known NP motifs, including frame-like and core-shell morphologies, in Au-Pt systems. We leverage insights gained from these studies to induce a controlled transition from redox- to surface chemistry-mediated growth pathways, resulting in the formation of Pt NPs in epitaxial contact and linear alignment along a gold nanoprism substrate. Mechanistic investigations using a combination of electron microscopy and (195)Pt NMR spectroscopy identify Pt(IV) speciation as a crucial parameter for understanding and controlling the formation of Pt-containing NPs. Combined, these findings point toward fully bottom-up methods for deposition and organization of NPs on colloidal plasmonic substrates.
authors.affiliation: Department of Chemistry, University of Pittsburgh , Pittsburgh, Pennsylvania 15260, United States.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Straney
authors.forename: Lauren E
authors.initials: LE
authors.lastname: Marbella
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Andolina
authors.forename: Noel T
authors.initials: NT
authors.lastname: Nuhfer
authors.forename: Jill E
authors.initials: JE
authors.lastname: Millstone