Epitaxial Overgrowth of Platinum on Palladium Nanocrystals
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 Lab. (BNL), Upton, NY (United States)
- Sponsoring Organization:
- DOE - OFFICE OF SCIENCE
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 1019443
- Report Number(s):
- BNL-94585-2011-JA; KC0201010; TRN: US201115%%118
- Journal Information:
- Nanoscale, Vol. 2, Issue 11; ISSN 2040-3364
- Country of Publication:
- United States
- Language:
- English
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