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Shape‐controlled synthesis of Pt nanocrystals: an evolution of the tetrahedral shape
Author(s) -
Yu YingTao,
Xu BoQing
Publication year - 2006
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1123
Subject(s) - crystallite , chemistry , nanocrystal , aqueous solution , transmission electron microscopy , crystallography , tetrahedron , single crystal , absorption spectroscopy , crystal (programming language) , morphology (biology) , particle size , selectivity , nanotechnology , materials science , optics , catalysis , organic chemistry , programming language , physics , computer science , biology , genetics
Platinum nanocrystals with sizes smaller than 10 nm are obtained by H 2 ‐reduction of aqueous K 2 PtCl 6 in the presence of different concentrations of poly ( N ‐vinyl‐2‐pyrrolidone; PVP: M w ≈ 360 000) at pH = 2.5–7.0. Tetrahedral Pt nanocrystals (3–10 nm) are produced with high selectivity (73–83% by number) at moderate PVP:K 2 PtCl 6 ratios. The co‐existing round/spheroidal crystallites are found to be smaller than the tetrahedrally shaped ones in the systems of varying K 2 PtCl 6 :PVP ratios. Careful examinations of the particle size and shape evolution of the crystallites at different stages of the crystal growth with transmission electron microscopy (TEM) and ultraviolet–visible absorption spectroscopy (UV–vis) suggest that the tetradedrally shaped Pt crystallites share the same type of nuclei with the round ones at the early stage of the crystal formation. Evolution of the tetrahedral shape happens in the later slow crystal growth. Copyright © 2006 John Wiley & Sons, Ltd.