Preparation of gold nanoparticles using reactive species produced in room-temperature ionic liquids by accelerated electron beam irradiation

Abstract

Au nanoparticles that are expected to be a key material for supporting future technologies were produced with brief accelerated electron beam irradiation to various 1-alkyl-3-methylimidazolium cation ([R₁MeIm]⁺)-based room-temperature ionic liquids (RTILs) with aurate. The resulting Au nanoparticles were able to remain in a nearly-monodispersed state in the RTILs for several weeks at least although the surface was not covered with a stabilizing agent, which is usually employed so as to prevent aggregation behaviour. The particle size increased with increasing the irradiation dose as well as decreasing the alkyl chain length of the [R₁MeIm]⁺ if the RTIL consisted of the same anion species. The shapes of the Au nanoparticles obviously altered with the anionic species in the RTILs used for the preparation.