Fabrication of silver hollow microspheres by sodium hydroxide in glycerol solution

Silver hollow microspheres have been carried out by the reduction of silver sulfate with the mixture solution of glycerol and sodium hydroxide. The effect of reaction temperature and time on the average size of silver particles and thickness of multi-porous silver layer covering the silver sulfate core were investigated. The thickness of silver layer increases with both temperature and time i.e., approximately 0.1 μm at temperature 30 °C for 3 min and 0.3 μm at temperature 60 °C for 60 min. Moreover the average silver particle sizes increased from 80 nm to 115 nm after the reaction temperature was increased from 30 to 60 °C, but an increase in the reaction time affected the silver particle size only slightly, and tended to produce silver particles with a higher aggregation. The specific surface areas were also investigated by BET analysis. The microspheres have a coral-like surface morphology. A change in the reduction temperature and time also resulted in a change in the surface morphology of the microspheres.