Synthesis and Characterization of Pt Dendrimer-Encapsulated Nanoparticles: Effect of the Template on Nanoparticle Formation

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm8004198· OSTI ID:959641

Knecht, M; Weir, M; Myers, V; Pyrz, W; Ye, H; Petkov, V; Buttrey, D; Frenkel, A; Crooks, R

In this article, we provide a detailed description of the synthesis and properties of Pt dendrimer-encapsulated nanoparticles (DENs) prepared using sixth-generation, hydroxyl-terminated, poly(amidoamine) (PAMAM) dendrimers (G6-OH) and three different PtCl42-/G6-OH ratios: 55, 147, and 240. Results obtained from UV-vis spectroscopy, X-ray photoelectron spectroscopy, electron microscopy, X-ray absorption spectroscopy, and high-energy X-ray diffraction show that only a fraction of the Pt2+/dendrimer precursors are reduced by BH4- and that the reduction process is highly heterogeneous. That is, after reduction each Pt2+/dendrimer precursor complex is either fully reduced, to yield a DEN having a size and structure consistent with the original PtCl42-/dendrimer ratio used for the synthesis, or the precursor is not reduced at all. This result is consistent with an autocatalytic process that entails slow formation of a nascent catalytic Pt seed within the dendrimer, followed by rapid, catalytic reduction of nearby Pt2+ ions. Details concerning the formation of the Pt2+/dendrimer precursor are also discussed.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 959641
• Report Number(s): BNL--82627-2009-JA
• Journal Information: Chemistry of Materials, Journal Name: Chemistry of Materials Vol. 20; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
ELECTRON MICROSCOPY
PRECURSOR
SEEDS
SPECTROSCOPY
SYNTHESIS
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY
national synchrotron light source