skip to main content

SciTech ConnectSciTech Connect

Title: Direct observation and analysis of yolk-shell materials using low-voltage high-resolution scanning electron microscopy: Nanometal-particles encapsulated in metal-oxide, carbon, and polymer

Nanometal particles show characteristic features in chemical and physical properties depending on their sizes and shapes. For keeping and further enhancing their features, the particles should be protected from coalescence or degradation. One approach is to encapsulate the nanometal particles inside pores with chemically inert or functional materials, such as carbon, polymer, and metal oxides, which contain mesopores to allow permeation of only chemicals not the nanometal particles. Recently developed low-voltage high-resolution scanning electron microscopy was applied to the study of structural, chemical, and electron state of both nanometal particles and encapsulating materials in yolk-shell materials of Au@C, Ru/Pt@C, Au@TiO{sub 2}, and Pt@Polymer. Progresses in the following categories were shown for the yolk-shell materials: (i) resolution of topographic image contrast by secondary electrons, of atomic-number contrast by back-scattered electrons, and of elemental mapping by X-ray energy dispersive spectroscopy; (ii) sample preparation for observing internal structures; and (iii) X-ray spectroscopy such as soft X-ray emission spectroscopy. Transmission electron microscopy was also used for characterization of Au@C.
Authors:
; ;  [1] ;  [2] ; ;  [3] ;  [2] ;  [4]
  1. JEOL Ltd., SM Business Unit, Tokyo (Japan)
  2. Graduate School of EEWS, WCU/BK21+, KAIST, Daejeon 305-701 (Korea, Republic of)
  3. Department of Heterogeneous Catalysis, Max-Planck-Institut für Kohlenforschung, Mülheim (Germany)
  4. (Sweden)
Publication Date:
OSTI Identifier:
22415219
Resource Type:
Journal Article
Resource Relation:
Journal Name: APL materials; Journal Volume: 2; Journal Issue: 11; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CARBON; COALESCENCE; ELECTRIC POTENTIAL; ELECTRONS; EMISSION SPECTROSCOPY; GOLD; IMAGES; MAPPING; NANOSTRUCTURES; PHYSICAL PROPERTIES; PLATINUM; POLYMERS; SAMPLE PREPARATION; SCANNING ELECTRON MICROSCOPY; TITANIUM OXIDES; TRANSMISSION ELECTRON MICROSCOPY; X-RAY SPECTROSCOPY