Less chemicals for more controlled syntheses: on the benefits of mixtures of alcohols for room temperature surfactant-free colloidal syntheses of gold nanoparticles

Abstract

The full exploitation of nanoparticle (NP) properties requires their controlled syntheses, ideally achieved by more sustainable strategies. We report on the benefits of using mixtures of ethanol and glycerol for the room temperature syntheses of stable surfactant-free colloidal gold (Au) NPs in alkaline water–alcohol solutions. Using [ethanol + glycerol] mixtures with a low amount of glycerol, e.g. only 2 v%, improves the size control over the Au NPs and enables the total alcohol content to be lowered for a successful synthesis. The results provide solid foundation towards the rational development of more sustainable syntheses of colloidal NPs.