Air stable core–shell multilayer metallic nanoparticles synthesized by RAPET: fabrication, characterization and suggested applications

We have developed a novel synthesis of carbon coated Cu@Ag and Ag@Cu core–shell nanoparticles by a rapid, cheap, solvent-less and straightforward method of fabrication. The technique by which these composites are prepared is called RAPET (Reaction under Autogenic Pressure at Elevated Temperatures). The X-ray diffraction measurements confirm the presence of two separated phases – silver and copper – and negate the possibility of alloy formation. Elemental mapping obtained by electron energy-loss spectroscopy (EELS) and line-scan analysis confirm the core–shell structure. Colloidal suspensions of Cu@Ag@C nanostructures were prepared and their stability was examined by dynamic light scattering (DLS) measurements. The mechanism of formation of the multilayer nanostructures is discussed here.