Synthesis and plasmonic properties of monodisperse Au–Ag alloy nanoparticles of different compositions from a single-source organometallic precursor

Abstract

Monodisperse Au–Ag alloy nanoparticles of different compositions are prepared through the mild decomposition of the bimetallic precursor [Au₂Ag₂(C₆F₅)₄(OEt₂)₂]_n in an organic solvent using hexadecylamine (HDA) as a stabilizing ligand. The effects of different reaction parameters on the size and composition of the nanoparticles, such as the metal : HDA ratio, the use of H₂ reducing gas or the solvent (toluene, THF or mesitylene), have been studied through TEM, HRTEM, EDS, UV/Vis and ¹⁹F NMR spectroscopy. The localized surface plasmon resonance (LSPR) displayed by the spherical Au–Ag nanoparticles can be tuned as a function of the metal composition.