INOR 59 |
| Polyacrylate-capped Pt nanoparticles were synthesized and assembled in poly(diallyldimethylammonium chloride) on electrodes. Electrochemical characterization using hydrogen underpotential deposition (Hupd) of 2.5 ± 0.6 nm diameter particles revealed well-resolved adsorption peaks at (100) and (110) crystal sites. Nanocrystal surface characterization using Hupd allowed detection of (111) sites and (100) long-range order at differently shaped (e.g., tetrahedral, and cubic) polyacrylate-capped Pt nanoparticles. The modified-Pt nanoparticle assemblies were electrocatalytically active for oxygen reduction, hydrogen evolution and oxidation, and hydrogen peroxide reduction and oxidation. Nanostructured electrodes were assembled at varying surface coverage at sub-monolayer, or in multilayered assembly, and the surface coverage was calculated from Hupd and confirmed by TEM. Oxygen reduction and related charge transfer processes were investigated in relation to Pt nanoparticle surface coverage, and in comparison to the behavior of a bulk Pt electrode. The implications for studies of the crystallite size effect at Pt will be discussed. |
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Nanoscience: Synthesis and Characterization
8:30 AM-12:10 PM, Sunday, August 19, 2007 BCEC -- 209, Oral
Division of Inorganic Chemistry |