High photocatalytically active cocoons-like TiO2/SiO2 synthesized by hydrothermal process and subsequent calcination at 900 °C

TiO2/SiO2 nanoparticles with cocoons-like morphology were synthesized by one-pot hydrothermal process and subsequent calcination at 900 degrees C, using tetrabutyl titanate and tetraethoxysilane as starting materials. The effects of calcination temperature on the morphology, crystalline phase, band gap, microtexture as well as photocatalytic activity of TiO2/SiO2 were investigated by TEM, XRD, TG, IR, DRS and N-2 adsorption-desorption isothermals. The calcination caused the shrinkage of highly porous SiO2 gel shell grafted on TiO2 crystallite and led to the formation of cocoons-like structure, and the crystallite size and the anatase phase of TiO2 can be maintained up to 900 degrees C and 1100 degrees C, respectively. The TiO2/SiO2 photocatalyst calcined at 900 degrees C showed a higher photocatalytic activity compared with commercial P25.