Synthetic Methods for Nanomaterials of Controlled Composition and Morphology

Tienes, Bryan Matthew

Graduate Thesis Or Dissertation

Synthetic Methods for Nanomaterials of Controlled Composition and Morphology Public Deposited

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Citations

Citeable URL: https://scholar.colorado.edu/concern/graduate_thesis_or_dissertations/1j92g757b

Abstract

Novel heterogeneous catalysts are required to meet the energy needs of future generations and reduce emissions of carbon dioxide. Many of the recent advances in catalysis have been in the study of nanoparticles. The catalytic activity of nanoparticles relies heavily on their composition, crystal morphology, and surface structure. The best approach for the discovery of new catalysts is to first identify the most catalytically active elemental compositions and then synthesize nanoparticles of those compositions in the most active morphology. This dissertation covers three projects, each with the goal of addressing deficiencies the methods currently available for that catalyst discovery approach. The work presented in Chapter 2 addressed deficiencies in the current synthetic methods used to discover materials with the most active composition. Presented is a method for synthesizing combinatorial catalysts arrays from precursor nanoparticles. Many researchers have turned to combinatorial methods to identify heterogeneous catalysts due to the difficultly in predicting active catalytic compositions a priori. First the synthetic method was demonstrated for generating arrays of gold and silver alloy nanoparticles, and then platinum and ruthenium nanoparticles were used to demonstrate the ability of the synthetic method to generate arrays for a combinatorial study. The final two chapters focused on understanding the role of capping ligands in nanoparticle synthesis and then utilizing their functionality to direct the synthesis of nanoparticles to produce a desired surface structure. Chapter 3 discusses the role of the popular capping ligands, alkyl phosphonic acids, in the synthesis of anisotropic zinc oxide nanoparticles. Chapter 4 describes work with the goal of using in vitro selection procedures to select RNA capable of directing the growth of platinum nanoparticles so that the desired surface structure is exposed on the surface of the nanoparticle product.

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