CHED 321 |
| A variety of metallic nanoparticles have been used to catalyze the growth of carbonaceous nanostructures (e.g., nanotubes, nanofibers, etc.). The most heavily used compositions include Fe, FexOy, Co, Ni, Ni/Y, and Co/Ni species. Carbon nanotubes are thought to grow from these catalysts via a vapor-liquid-solid (VLS) mechanism, which was first postulated ca. 30 years ago for the growth of semiconductor wires. We recently discovered a method to generate carbonaceous nanostructures via a surface-nucleation mechanism, whereby growth occurs at room temperature – far below the melting point of the catalyst seed. This route consists of simple benchtop stirring of a benzene suspension of potassium metal, tetrachloroethylene, and an iron-based catalyst. Though the product consists of amorphous carbon nanofibers (CNFs) at room temperature, we have observed graphitized carbon nanotubes (CNTs) at higher temperatures within sealed high-pressure tubes. Herein, we will describe the morphology of the products (as-grown and ex situ annealed) using a suite of XRD, FESEM, and HRTEM techniques. |
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Undergraduate Research Poster Session: Nanotechnology
11:00 AM-1:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster
Division of Chemical Education |