Nanostructure of wet-chemically prepared, polymer-stabilized silver-gold nanoalloys over the entire composition range

Bimetallic silver-gold nanoparticles were prepared by co-reduction using citrate and tannic acid in aqueous solution and colloidally stabilized with poly(N-vinylpyrrolidone) (PVP). The full composition range of silver:gold from 0:100 to 100:0 (n:n) was prepared with steps of 10 mol%. The nanoparticles were spherical, monodisperse, and had a diameter of ~6 nm, except for Ag:Au 90:10 nanoparticles and pure Ag nanoparticles which were slightly larger. The size of the nanoalloys was determined by differential centrifugal sedimentation (DCS) and transmission electron microscopy (TEM).