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 °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 N2 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 °C and 1100 °C, respectively. The TiO2/SiO2 photocatalyst calcined at 900 °C showed a higher photocatalytic activity compared with commercial P25.