Ag/Rh bimetallic nanoparticles formed by self-assembly from Ag and Rh monometallic nanoparticles in solution

The plasmon absorption band of colloidal dispersions of poly(N-vinyl-2-pyrrolidone)-protected Ag nanoparticles was extinguished within several minutes by the addition of Rh nanoparticles sol. Transmission electron micrographs and X-ray diffraction measurements have shown that this phenomenon is due to that the physical mixture of Ag and Rh nanoparticles spontaneously generates the bimetallic nanoparticles with A-core/Rh-shell structure.