Gold Nanowires from Nanorods.

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Gold nanowires (AuNWs) are crucial for microelectronics and plasmonics due to their low resistance.
• Existing synthesis methods struggle with purity, length control (typically <10 μm), and solvent dispersibility.
• Challenges include co-existing impurities like nanorods, platelets, and spherical particles.

Purpose of the Study:

• To develop a one-step synthesis for pure, solvent-dispersible gold nanowires (AuNWs) with controlled lengths up to 25 μm.
• To investigate the microwave responsiveness of synthesized AuNWs.

Main Methods:

• Utilized pentahedrally twinned gold nanorods (AuNRs) as seed particles for controlled growth.
• Employed a low pH growth solution with HCl to facilitate Au(I) to Au(0) reduction on AuNR surfaces.
• Controlled AuNW length by managing the supply of Au(I) ions, analogous to 'living' polymerization.

Main Results:

• Achieved synthesis of extremely long AuNWs (up to 25 μm) with precise dimensional control.
• Demonstrated that AuNWs longer than 6 μm exhibit responsiveness to microwave radiation.
• Observed the formation of sharp kinks in AuNWs upon microwave exposure without disintegration.

Conclusions:

• The developed method offers a significant advancement in synthesizing high-quality, long gold nanowires.
• The precise length control and microwave responsiveness open new avenues for applications in electronics and materials science.
• The findings pave the way for novel functional nanomaterials with tunable properties.