N,N-Dimethylformamide-Assisted Shape Evolution of Highly Uniform and Shape-Pure Colloidal Copper Nanocrystals

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Controlling nanocrystal morphology is crucial for tuning their properties.
• Copper nanocrystals (Cu NCs) have shown promise in various applications.
• Previous methods lacked precise control over Cu NC shape and uniformity.

Purpose of the Study:

• To present the first N,N-dimethylformamide (DMF)-assisted synthesis of uniform and shape-pure copper nanocrystals (Cu NCs).
• To investigate the systematic shape evolution of Cu NCs.
• To understand the underlying mechanisms of shape control and its impact on properties.

Main Methods:

• Colloidal synthesis of Cu NCs via copper (I) bromide disproportionation.
• Systematic variation of DMF concentration under high-temperature conditions.
• First-principles density functional theory (DFT) calculations to study surface stability.
• Investigation of plasmonic properties in acetonitrile and electrocatalytic activity in methanol oxidation.

Main Results:

• Achieved highly uniform and shape-pure Cu NCs.
• Demonstrated systematic shape evolution from cubes ({100} facets) to spheres to octahedrons ({111} facets) with increasing DMF.
• DFT calculations revealed the role of DMF in altering relative surface energies.
• Observed distinct shape-dependent plasmonic and electrocatalytic properties.

Conclusions:

• DMF is an effective agent for precisely controlling Cu NC morphology.
• The shape evolution is governed by DMF's interaction with crystal facets.
• Shape-controlled Cu NCs exhibit tunable plasmonic behavior and enhanced electrocatalytic activity for methanol oxidation.