Preferential Outward Diffusion of Cu during Unconventional Galvanic Replacement Reactions between HAuCl4 and Surface-limited Cu Nanocrystals

Published

August 25, 2011

Author(s)

Yonglin Liu, Angela R. Hight Walker

Abstract

Using pre-synthesized Cu-Cu1.81S hetero-oligomer and Cu-Cu2S heterodimer NCs as templates and reactants, the addition of HAuCl4 leads to the preferential outward diffusion of Cu, evidenced by the formation of straight or kinked CuAu nanowires, respectively. The directional structures of the as-prepared CuAu nanowires elucidate the outward diffusion pathway of Cu, visualized by alloying Cu with newly produced Au. The time-dependent growth of these nanowires allows us to calculate the diffusion coefficients of Cu during these processes for the first time. This protocol can be likely extended to other similar metal NC systems, providing a simple and cost-effective method for visualization and kinetic investigation of metal diffusions in nanoscale materials.

Citation

ACS Nano

Volume

5

Issue

9

Pub Type

Journals

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DOI Link

Keywords

Cu diffusion, diffusion coefficient, HAuCl4, surface-limited Cu nanocrystals, unconventional galvanic replacement reaction

Citation

Liu, Y. and Hight, A. (2011), Preferential Outward Diffusion of Cu during Unconventional Galvanic Replacement Reactions between HAuCl4 and Surface-limited Cu Nanocrystals, ACS Nano, [online], https://doi.org/10.1021/nn200565y (Accessed May 10, 2025)