Seed-Morphology-Directed Synthesis of Concave Gold Nanocrystals with Tunable Sizes

Area of Science:

• Materials Science
• Nanotechnology
• Physical Chemistry

Background:

• Gold nanocrystals are crucial in various applications due to their unique optical and electronic properties.
• Controlling the morphology of gold nanocrystals is key to tuning their performance.
• Previous studies have focused on convex shapes, leaving concave morphologies underexplored.

Purpose of the Study:

• To fabricate concave gold (Au) nanocrystals with controlled morphologies and sizes.
• To investigate the influence of reaction parameters on nanocrystal shape.
• To evaluate the optical and electrochemical properties of the synthesized concave Au nanocrystals.

Main Methods:

• Seeded growth method using well-defined Au seeds.
• Systematic investigation of reaction parameters, including capping agents and silver ion (Ag+) concentration.
• Characterization using UV-vis extinction spectroscopy and cyclic voltammetry.

Main Results:

• Successfully synthesized cubic and rodlike Au nanocrystals with concave features.
• Observed shape evolution during the growth process.
• Concave Au nanocrystals showed a red shift in absorbance peaks and distinct electrochemical behavior compared to spherical counterparts.

Conclusions:

• The seeded growth approach enables the fabrication of concave Au nanocrystals with tunable sizes and shapes.
• The concave morphology offers advantages in optical and electrochemical properties.
• This work provides a pathway for designing advanced gold nanostructures for specific applications.