Login / Signup

Revealing the Phase Separation Behavior of Thermodynamically Immiscible Elements in a Nanoparticle.

Peng-Cheng ChenMengyu GaoSunmoon YuJianbo JinChengyu SongMiquel B SalmeronMary C ScottPeidong Yang
Published in: Nano letters (2021)
Phase-separation is commonly observed in multimetallic nanomaterials, yet it is not well understood how immiscible elements distribute in a thermodynamically stable nanoparticle. Herein, we studied the phase-separation of Au and Rh in nanoparticles using electron microscopy and tomography techniques. The nanoparticles were thermally annealed to form thermodynamically stable structures. HAADF-STEM and EDS characterizations reveal that Au and Rh segregate into two domains while their miscibility is increased. Using aberration-corrected HAADF-STEM and atomic electron tomography, we show that the increased solubility of Au in Rh is achieved by forming Au clusters and single atoms inside the Rh domains and on the Rh surface. Furthermore, based on the three-dimensional reconstruction of a AuRh nanoparticle, we can visualize the uneven interface that is embedded in the nanoparticle. The results advance our understanding on the nanoscale thermodynamic behavior of metal mixtures, which is crucial for the optimization of multimetallic nanostructures for many applications.
Keyphrases
  • electron microscopy
  • sensitive detection
  • reduced graphene oxide
  • iron oxide
  • genome wide
  • gold nanoparticles
  • gene expression
  • high resolution
  • single cell
  • visible light
  • quantum dots