A facile colloidal templating method to monodisperse hollow Ag and Ag/Au submicrometer spheres

Monodisperse hollow Ag and Ag/Au submicrometer spheres have been synthesized by a facile colloidal templating method. In this method, the silver nanoparticle seeds are synthesized on the silica colloids surface through the electroless plating approach to avoid the complex surface functionalization, and the subsequent seeding growth and dissolving silica core are carried out simultaneously. The as-prepared hollow spheres remain mostly the fine monodispersity and spheric shape of the silica core, and can self-assemble directly into ordered structure, which is realized for the first time. The method is simple and versatile, and can be used to prepare other monodisperse hollow composite metallic or bimetallic spheres.