Preparation of monodispersed microporous SiO2 microspheres with high specific surface area using dodecylamine as a hydrolysis catalyst

A novel and simple method for the synthesis of monodispersed microporous SiO2 microspheres with high specific surface area was developed by hydrolysis of tetraethoxysilane (TEOS) in a water–ethanol mixed solution and using dodecylamine (DDA) as hydrolysis catalyst and template. The as-prepared products were characterized with differential thermal analysis–thermogravimetry, scanning electron microscopy, high-resolution transmission electron microscopy, small angle X-ray diffraction and nitrogen adsorption. The effects of experimental conditions including hydrolysis temperatures, calcination temperature and concentrations of TEOS and DDA on the morphology and pore parameters of the as-prepared SiO2 microspheres were investigated and discussed. The results showed that hydrolysis temperature and concentrations of TEOS and DDA are important parameters for the control of size and morphology of particles. The specific surface area and specific pore volume of the as-prepared SiO2 microspheres increased with increasing DDA concentration and calcination temperature. DDA may act not only as a good hydrolysis catalyst but also as a template for the formation of monodispersed SiO2 microspheres with high specific surface area. This research may provide new insight into the synthesis of monodispersed microporous SiO2 microspheres.