Skeletal octahedral nanoframe with cartesian coordinates via geometrically precise nanoscale phase segregation in a Pt@Ni core-shell nanocrystal

Aram Oh, Hionsuck Baik, Dong Shin Choi, Jae Yeong Cheon, Byeongyoon Kim, Heejin Kim, Seong Jung Kwon, Sang Hoon Joo, Yousung Jung, Kwangyeol Lee

Research output: Contribution to journalArticle

116 Citations (Scopus)

Abstract

Catalytic properties of nanoparticles can be significantly enhanced by controlling nanoscale alloying and its structure. In this work, by using a facet-controlled Pt@Ni core-shell octahedron nanoparticle, we show that the nanoscale phase segregation can have directionality and be geometrically controlled to produce a Ni octahedron that is penetrated by Pt atoms along three orthogonal Cartesian axes and is coated by Pt atoms along its edges. This peculiar anisotropic diffusion of Pt core atoms along the 〈100〉 vertex, and then toward the 〈110〉 edges, is explained via the minimum strain energy for Ni-Ni pair interactions. The selective removal of the Ni-rich phase by etching then results in structurally fortified Pt-rich skeletal PtNi alloy framework nanostructures. Electrochemical evaluation of this hollow nanoframe suggests that the oxygen reduction reaction (ORR) activity is greatly improved compared to conventional Pt catalysts.

Original languageEnglish
Pages (from-to)2856-2867
Number of pages12
JournalACS Nano
Volume9
Issue number3
DOIs
Publication statusPublished - 2015 Mar 24

Keywords

  • alloy
  • crystal growth
  • nanoparticles
  • phase segregation
  • platinum

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)

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