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A Mechanistic Study on the Nucleation and Growth of Au on Pd Seeds with a Cubic or Octahedral Shape
Author(s) -
He Guannan,
Zeng Jie,
Jin Mingshang,
Zhang Hui,
Lu Ning,
Wang Jinguo,
Kim Moon J.,
Xia Younan
Publication year - 2012
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201200205
Subject(s) - bimetallic strip , ascorbic acid , nucleation , nanocrystal , octahedron , materials science , shell (structure) , reducing agent , catalysis , chemical engineering , crystallography , nanotechnology , chemistry , crystal structure , organic chemistry , composite material , food science , engineering
This article reports a systematic study on the seed‐mediated growth of Pd–Au bimetallic nanocrystals with a variety of controlled morphologies. The key to the success of this synthesis is to manipulate the reaction kinetics by controlling a set of experimental parameters, which include the amount of ascorbic acid used as a reductant, the amount of HAuCl 4 as a precursor to elemental Au, the reaction temperature, and the type of seeds employed. Starting from Pd nanocubes of 18 nm in edge length, Pd–Au bimetallic nanocrystals with a number of morphologies, which includes hybrid dimers, core–shell nanocubes with flat faces, and core–shell nanocubes with concave faces could all be obtained by simply speeding up the reduction of HAuCl 4 . The same synthesis and control could also be extended to seeds based on Pd octahedrons. For the first time, it was possible to generate Pd@Au core–shell nanocubes and octahedrons with concave faces. The Pd@Au core–shell nanocubes with concave faces exhibited enhanced activity in catalyzing the oxidization of ascorbic acid relative to their counterparts with flat faces or the cubic Pd seeds.