Facile preparation of monodispersed SiO2/TiO2 composite microspheres with high surface area

Monodispersed nanoporous SiO2/TiO2 composite microspheres with high specific surface areas were prepared by depositing titania colloid particles on the surface of monodispersed microporous silica microspheres using a simple electrostatic attraction strategy, and then calcined at 600 °C for 4 h. The as-prepared products were characterized with differential thermal analysis and thermogravimetric (DTA/TG), scanning electron microscopy (SEM), X-ray diffraction (XRD), nitrogen adsorption and X-ray photoelectron spectroscopy (XPS). It was found that uniform titania coatings could be deposited on the surface of silica microspheres by adjusting the pH value of the reaction solution to an optimal pH value ranges of about 4–5. The specific surface area and pore volume of the SiO2/TiO2 composite microspheres calcined at 600 °C were 960 m2 g−1 and 0.48 mL g−1, respectively.