Template-less and surfactant-free solvent-driven direct synthesis of urchin-like gold nanoparticles in anisole

Abstract

In this study, we present a simple template-less and surfactant-free method for the synthesis of urchin-shaped gold nanoparticles. Anisole, the reaction solvent also acted as the reducing agent. When compared with other harsher solvent-mediated methods for the synthesis of gold nanoparticles, the method presented here allows the formation of nanoparticles at the relatively low temperature of 60°C. The effect of reaction time was studied, and it was observed that the urchin-shaped particles initially formed transformed into smooth-edged particles when the reaction was continued for more than 30 minutes owing to the thermodynamic instability of gold nanourchins. The effect of added capping agents such as dodecanethiol, hexadecylamine and polyvinylpyrrolidone (PVP) was also studied, and it was found that nanoparticles were not formed in their presence. The gold nanosystems obtained in this study were characterised by transmission electron microscopy and UV-visible absorption spectroscopy.

Bespoke nanostars: synthetic strategies, tactics, and uses of tailored branched gold nanoparticles

“…Poonthiyil et al reported surfactant-free AuNUs through a solvent-directed synthesis at a relatively mild temperature of 60 °C. 91 HAuCl 4 (1 mM) was added to 50 mL of anisole solvent and allowed reaction time resulting in AuNUs (1 min) or the more thermally stable quasispherical AuNPs (15 min). Interestingly, the reaction failed to result in any gold nanostructures in the presence of thiol or amine capping agents.…”