Nanoscale platinum materials have been transformative components of many critical technologies including catalytic converters and fuel cells. Combining platinum 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 syntheses of Pt-based particles is challenging due to the complex speciation of platinum ion precursors. Here, we study the impact of this speciation on the appearance of well-known motifs such as frame-like and core-shell morphologies in Au-Pt nanoparticle systems. We then use this insight to induce a controlled transition from surface chemistry to redox-mediated growth pathways in the resulting multi-metallic nanoparticles. The reaction is followed by electron microscopy techniques, as well as X-ray photoelectron spectroscopy, inductively coupled plasma mass spectrometry, and <sup>195</sup>Pt-NMR. Taken together, these studies indicate a crucial parameter in the synthesis of Pt-based nanomaterials and should shed light on seemingly similar synthetic routes that produce disparate particle outcomes. The elucidation of such mechanistic features allowed the observation of ligand supramolecular assembly as a promising tool for on-particle patterning, and ultimately the generation of site-specific, light-mediated heterogeneous catalysts.

Mechanisms of on-colloid nanoparticle growth

249th National Meeting (2015)

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