Fabrication of freestanding SiO2-TiO2 composite by a facile one pot method

A freestanding SiO2-TiO2 monolith with bicontinuous structure was prepared via a one pot sol-gel reaction. This monolith was fully characterized by using field emission scanning electron microscopy (FE-SEM), nitrogen adsorption and X-Ray diffraction (XRD). Synthesized SiO2-TiO2 monolith possesses great mechanical strength and interconnected macropores (throughpores, textural pores) on the micrometer scale as well as skeleton pores in nanoscale, and also possesses an anatase TiO2 crystalline structure. Photo-catalytic breakdown of aqueous methylene blue (MB) with UV light was chosen to evaluate photocatalytic efficacy of the SiO2-TiO2 catalyst. These photodegradation activities indicated that MB decomposed completely within 180min and the SiO2-TiO2 catalyst was readily separated from the reaction system and easily regenerated. Moreover, the photocatalytic activity of the monolithic catalyst remained unchanged after four catalytic cycles and the morphology was still intact.