Synthesis of icosahedral gold particles by a simple and mild route

Abstract

In this work we prepared icosahedral gold particles using hydrogen tetrachloroaurate(III) hydrate (HAuCl₄·3H₂O) as precursor and poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers as both reductant and directing agent. The products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis, and UV–Vis spectroscopy. The effects of temperature, reaction time, concentration of the precursor, and structure and concentration of the copolymers on the morphology and size of the gold particles were investigated. It was demonstrated that icosahedral gold nanoparticles can be formed under a wide range of experimental conditions and the size of the obtained icosahedral particles can be tuned from 100 nm to 1 μm by varying experimental conditions. This method has some obvious advantages, such as being simple and green, and the particle size can be easily controlled.