Ethylenediamine Promotes Cu Nanowire Growth by Inhibiting Oxidation of Cu(111)

Abstract

The synthesis of metal nanostructures usually requires a capping agent that is generally thought to cause anisotropic growth by blocking the addition of atoms to specific crystal facets. This work uses a series of electrochemical measurements with a quartz crystal microbalance and single-crystal electrodes to elucidate the facet-selective chemistry occurring in the synthesis of Cu nanowires. Contrary to prevailing hypotheses, ethylenediamine, a so-called capping agent in the synthesis of Cu nanowires, causes anisotropic growth by increasing the rate of atomic addition to (111) facets at the end of a growing nanowire relative to (100) facets on the sides of a nanowire. Ethylenediamine increases the reduction rate of Cu(OH) on a Cu(111) surface relative to Cu(100) by selectively inhibiting the formation of Cu oxide on Cu(111). This work demonstrates how studying facet-selective electrochemistry can improve the understanding of the processes by which atoms assemble to form anisotropic metal nanostructures.

Emerging Novel Metal Electrodes for Photovoltaic Applications

“…Here, we will only review the approaches capable of large‐scale synthesis of Cu NWs with high aspect ratio. Wiley and co‐workers have performed great job by using ethylenediamine (EDA) as surfactant to synthesize Cu NWs and study their growth mechanisms . Cu(NO 3 ) 2 and hydrazine are generally used as the Cu ion source and reduction agent, and the reaction is carried out in a heavy basic aqueous solution through the addition of NaOH.…”

“…The rapid synthesis of Cu NWs with high aspect ratio of 5700 has been demonstrated . Their recent work on the growth mechanism of Cu NW in the EDA‐mediated approach claims that EDA is functioned as a facet‐selective promoter of Cu atoms deposition on the {111} facets rather than a capping agent stabilizing the {100} facet to inhibit the lateral growth . However, the reduction agent of hydrazine is highly toxic and dangerously unstable, which should be stored and used with particular attention.…”

Electrochemical Investigation of the Growth of Copper Nanowires in the Presence of Ethylenediamine through Mixed Potential

“…[19][20][21][22] In effect, we can determine the solution condition that facilitates metal deposition or oxidation. Such simple approach also allows understanding of the kinetics and thermodynamics that influences the growth of metallic nanostructures in solution.19-22 More recent work by Kim et al 23 has presented similar method to explain the formation of Cu nanowires in the presence of surfactant.Therefore, in this work, we present a simple preparation process for Cu nanowires by electroless deposition in aqueous solution using EDA as surfactant. The effects of EDA concentration on the morphology and surface quality of the Cu nanowires were investigated.…”

“…19-22 More recent work by Kim et al 23 has presented similar method to explain the formation of Cu nanowires in the presence of surfactant.…”

“…Such simple approach also allows understanding of the kinetics and thermodynamics that influences the growth of metallic nanostructures in solution. [19][20][21][22] More recent work by Kim et al 23 has presented similar method to explain the formation of Cu nanowires in the presence of surfactant.…”