Abstract
Pt-on-Ag bimetallic nanoparticles were prepared based on a heterogeneous nucleation and growth method. Interestingly, platinum hollow nanoparticles could be obtained by selectively removing the silver cores from Pt-on-Ag nanoparticles. High-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray (EDX) analysis with a high-angle annular dark-field scanning transmission electron microscope (HAADF-STEM), and X-ray diffraction (XRD) were used to characterize these nanostructures. The observation that Pt hollows can be produced from Pt-on-Ag nanoparticles through the dissolution of Ag metal cores indicates that particle-on-particle nanodendrites were most likely derived from the products formed through the Stranski-Krastanov (SK) growth. The carbon-supported Pt hollow catalysts, which possessed much higher catalytic activity in oxygen reduction reaction (ORR) than the Pt-on-Ag nanoparticles, were also better than a commercial Pt catalyst (E-tek, 20% Pt). The nanometer-sized textures of the wall of Pt hollow spheres could contribute to the enhancement of the electrocatalytic activity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1098-1106 |
| Number of pages | 9 |
| Journal | Chemistry of Materials |
| Volume | 22 |
| Issue number | 3 |
| DOIs | |
| State | Published - Feb 9 2010 |
| Externally published | Yes |
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- Materials Chemistry