1 research outputs found
<i>In Situ</i> 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 <i>in situ</i> synchrotron X-ray scattering. We show that when PtÂ(II) and SnÂ(IV)
precursors are used, in contrast to a typical simultaneous reduction
mechanism, the PtSn NCs are formed through an initial reduction of
PtÂ(II) to form Pt NCs, followed by the chemical transformation from
Pt to PtSn. The kinetics derived from the <i>in situ</i> measurements shows fast diffusion of Sn into the Pt lattice accompanied
by reordering of these atoms into intermetallic PtSn structure within
300 s at the reaction temperature (∼280 °C). This crucial
mechanistic understanding enables the synthesis of well-defined PtSn
NCs with controlled structure and composition via a seed-mediated
approach. This type of <i>in situ</i> characterization can
be extended to other multicomponent nanostructures to advance their
rational synthesis for practical applications