1 research outputs found
Formation of Core–Shell AuCu@Ag Nanocrystals through the Nanoscale Kirkendall Effect
Polymetallic
nanocrystals (NCs) consist of multiple metal elements.
A powerful platform to achieve the flexible construction of polymetallic
NCs is highly desired but challenging. Herein, we devise a model system
that realizes metal atom diffusion between different NCs, resulting
in the formation of polymetallic NCs. The differential bond strength
between different metal atoms is proposed to initiate such metal atom
diffusion, and the specific high surface-to-volume ratio of the NCs
can expedite the diffusion process. Taking the Au–Cu–Ag
trimetallic system as an example, core–shell AuCu@Ag NCs were
successfully formed by combining AgCu NCs with Au NCs. The evolution
process was explored, and the gradual fusion of simple NCs into AuCu@Ag
NCs was unambiguously observed, which could be attributed to the larger
bond strength of Au–Cu than that of Ag–Cu. This work
offers an opportunity/platform in theory and experiment to expand
the synthesis framework as well as the polymetallic NC list