Preparation and characterization of silica-silver core-shell structural submicrometer spheres

Dense, uniform and thickness controllable silver layers were successfully coated on the mono-dispersed submicrometer silica spheres to obtain silica-silver core-shell structural spheres. The growth process of nanoscaled silver layer on silica spheres mainly includes two steps, i.e. nanoscaled nuclei formation and controllable layer growth process. The nuclear-growth mechanism is responsible for the deposition processes. The reagent concentrations and reaction time were found to be the key factors for the formation of controllable silver layer. High quality silver layer with dense and uniform structure was verified by transmission electron microscopy, X-ray diffraction and Energy Dispersive X-ray microanalysis.