Epitaxial Overgrowth of Platinum on Palladium Nanocrystals

Journal Article · Mon Nov 01 04:00:00 EDT 2010 · Nanoscale

DOI:https://doi.org/10.1039/c0nr00324g· OSTI ID:1019443

Jiang, M; Zhu, Y; Lim, B; Tao, J; Camargo, P H.C.; Ma, C; Xia, Y

This paper describes a systematic study on the epitaxial overgrowth of Pt on well-defined Pdnanocrystals with different shapes (and exposed facets), including regular octahedrons, truncated octahedrons, and cubes. Two different reducing agents, i.e., citric acid and L-ascorbic acid, were evaluated and compared for the reduction of K{sub 2}PtCl{sub 4} in an aqueous solution in the presence of Pdnanocrystal seeds. When citric acid was used as a reducing agent, conformal overgrowth of octahedral Pt shells on regular and truncated octahedrons of Pd led to the formation of Pd-Pt core-shell octahedrons, while non-conformal overgrowth of Pt on cubic Pd seeds resulted in the formation of an incomplete octahedral Pt shell. On the contrary, localized overgrowth of Pt branches was observed when L-ascorbic acid was used as a reducing agent regardless of the facets expressed on the surface of Pdnanocrystal seeds. This work shows that both the binding affinity of a reducing agent to the Pt surface and the reduction kinetics for a Pt precursor play important roles in determining the mode of Pt overgrowth on Pdnanocrystal surface.

• Research Organization: BROOKHAVEN NATIONAL LABORATORY (BNL)
• Sponsoring Organization: DOE - OFFICE OF SCIENCE
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1019443
• Report Number(s): BNL--94585-2011-JA; KC0201010
• Journal Information: Nanoscale, Journal Name: Nanoscale Journal Issue: 11 Vol. 2; ISSN 2040-3364
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AFFINITY
AQUEOUS SOLUTIONS
CITRIC ACID
KINETICS
PALLADIUM
PLATINUM
PRECURSOR
REDUCING AGENTS
SEEDS