posted on 2021-03-24, 23:15authored byJette
K. Mathiesen, Jonathan Quinson, Alexandra Dworzak, Tom Vosch, Mikkel Juelsholt, Emil T. S. Kjær, Johanna Schröder, Jacob J. K. Kirkensgaard, Mehtap Oezaslan, Matthias Arenz, Kirsten M. Ø. Jensen
Understanding
the formation of nanomaterials down to the atomic
level is key to rational design of advanced materials. Despite their
widespread use and intensive study over the years, the detailed formation
mechanism of platinum (Pt) nanoparticles remains challenging to explore
and rationalize. Here, various in situ characterization
techniques, and in particular X-ray total scattering with pair distribution
function (PDF) analysis, are used to follow the structural and chemical
changes taking place during a surfactant-free synthesis of Pt nanoparticles
in alkaline methanol. Polynuclear structures form at the beginning
of the synthesis, and Pt–Pt pair distances are identified before
any nanoparticles are generated. The structural motifs best describing
the species formed change with time, e.g., from [PtCl5–PtCl5] and [PtCl6–Pt2Cl6–PtCl6] to [Pt2Cl10–Pt3Cl8–Pt2Cl10]. The
formation of these polynuclear structures with Pt–Pt coordination
before the formation of the nanoparticles is suggested to account
for the fast nucleation observed in the synthesis.