A facile method to synthesize novel monodisperse core–shell structure of spherical silica at nanocrystalline copper

A kind of monodisperse core–shell structure of spherical silica at nanocrystalline copper has been successfully synthesized by a two-step synthesis method. A uniform spherical particle of silica was firstly fabricated according to the Stöber method. The obtained silica sample was coated by nanocrystalline copper through oxidation–reduction process. The effects of the volume of water added in the reaction system on particle size of silica were investigated. The particle size of the as-synthesized silica changed from about 170 ± 2 to 160 ± 2 nm with the volume of the added water change from 2.3 to 20 ml. When the volume of the added water was changed to 40 ml, the diameter of the obtained silica particle was about 210 ± 5 nm. The thickness of the coated copper can be controlled by using different sizes of silica particle. The formation mechanism was also discussed.