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

Monodisperse Au-Ag alloy nanoparticles of different compositions are prepared through the mild decomposition of the bimetallic precursor [Au 2Ag2(C6F5)4(OEt 2)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.