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This content will become publicly available on May 29, 2019

Title: In Situ X-ray Scattering Guides the Synthesis of Uniform PtSn Nanocrystals

Compared to monometallic nanocrystals (NCs), bimetallic ones often exhibit superior properties due to their wide tunability in structure and composition. A detailed understanding of their synthesis at the atomic scale provides crucial knowledge for their rational design. Here, exploring the Pt-Sn bimetallic system as an example, we study in detail the synthesis of PtSn NCs using in situ synchrotron X-ray scattering. We show that when Pt(II) and Sn(IV) precursors are used, in contrast to a typical simultaneous reduction mechanism, the PtSn NCs are formed through an initial reduction of Pt(II) to form Pt NCs, followed by the chemical transformation from Pt to PtSn. The kinetics derived from the in situ measurements shows fast diffusion of Sn into the Pt lattice accompanied by re-ordering of these atoms into intermetallic PtSn structure within 300 s at the reaction temperature (~280 oC). This crucial mechanistic understanding enables the synthesis of well-defined PtSn NCs with controlled structure and composition via a seed-mediated approach. Furthermore, this type of in situ characterization can be extended to other multicomponent nanostructures to advance their rational synthesis for practical applications.
Authors:
 [1] ;  [2] ;  [3] ; ORCiD logo [3] ;  [2]
  1. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  3. Stanford Univ., Stanford, CA (United States)
Publication Date:
Grant/Contract Number:
FWP 100250; AC02-76SF00515
Type:
Accepted Manuscript
Journal Name:
Nano Letters
Additional Journal Information:
Journal Volume: 18; Journal Issue: 6; Journal ID: ISSN 1530-6984
Publisher:
American Chemical Society
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; X-ray scattering; in situ; bimetallic; colloidal nanocrystals; phase transformation
OSTI Identifier:
1461328