Monodispersity control in the synthesis of monometallic and bimetallic quasi-spherical gold and silver nanoparticles

In order for the nanoparticles of Au and Ag to be useful for a wide range of applications, the tailorability of the nanoparticle properties through controlled changes of composition, size, shape, and crystal structure is absolutely essential. Furthermore, these nanoparticle attributes must be delivered in high monodispersity to assure a consistent application performance. High monodispersity is also a requirement for the assembly of nanoparticles into extended nanostructures or mesoscale devices which may be needed for some applications. This article describes a variety of colloidal synthesis methods in use today for the preparation of monodisperse Au, Ag, and bimetallic Au- Ag nanoparticles. The emphasis is on the analysis of the efficacy of each method for tailoring the nanoparticle size and crystal structure. The scope of work surveyed is confined to quasi-spherical nanoparticles in the size range from sub-nanometre to several tens of nanometres.