Redox-transmetalation process as a generalized synthetic strategy for core-shell magnetic nanoparticles

Woo Ram Lee, Min Gyu Kim, Joon Rak Choi, Jong Il Park, Seung Jin Ko, Sang Jun Oh, Jinwoo Cheon

Research output: Contribution to journalArticle

233 Citations (Scopus)

Abstract

Although multicomponent core-shell type nanomaterials are one of the highly desired structural motifs due to their simultaneous multifunctionalities, the fabrication strategy for such nanostructures is still in a primitive stage. Here, we present a redox-transmetalation process that is effective as a general protocol for the fabrication of high quality and well-defined core-shell type bimetallic nanoparticles on the sub-10 nm scale. Various core-shell type nanomaterials including Co@Au, Co@Pd, Co@Pt, and Co@Cu nanoparticles are fabricated via transmetalation reactions. Compared to conventional sequential reduction strategies, this transmetalation process has several advantages for the fabrication of core-shell type nanoparticles: (i) no additional reducing agent is needed and (ii) spontaneous shell layer deposition occurs on top of the core nanoparticle surface and thus prevents self-nucleation of secondarily added metals. We also demonstrate the versatility of these core-shell structures by transferring Co@Au nanoparticles from an organic phase to an aqueous phase via a surface modification process. The nanostructures, magnetic properties, and reaction byproducts of these core-shell nanoparticles are spectroscopically characterized and identified, in part, to confirm the chemical process that promotes the core-shell structure formation.

Original languageEnglish
Pages (from-to)16090-16097
Number of pages8
JournalJournal of the American Chemical Society
Volume127
Issue number46
DOIs
Publication statusPublished - 2005 Nov 23

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All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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