Preparation and characterization of SiO2@Fe2O3 core-shell catalysts

The monodisperse SiO2 microspheres with average diameter of 230 nm made by optimized Stöber method were used as core to prepare core-shell structure SiO2@Fe2O3 catalysts with different shell thickness through hydrolysis precipitation. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 physical adsorption and X-ray diffraction (XRD) were used to characterize the size, structure and morphology of catalysts and the effects of different preparation conditions on morphology were discussed. The characterization results indicate that SiO2@Fe2O3 catalysts possess obvious core-shell structure and the spherical morphology of catalyst is kept. Iron oxide nanoparticles are attached to the silica surface through hydroxyl-bond and a 2–10 nm thick dense shell is formed.