Preparation and photocatalytic properties of nanometer-sized magnetic TiO ₂/SiO ₂/CoFe ₂O ₄Composites

Magnetic TiO ₂/SiO ₂/CoFe ₂O ₄ nanoparticles (TiO ₂/SCFs) were prepared by a sol-gel process in a reverse microemulsion combined with solvent-thermal technique. TiO2/SCFs were characterized by Fourier transform infrared spectrometry, thermogravimetric analysis-differential scanning calorimetry, X-ray diffraction, Raman spectrometry, TEM, BET specific surface area measurement, and magnetic analysis. Structure analyses indicated that TiO ₂/SCFs presented a core-shell structure with TiO ₂ uniformly coating on SiO ₂/CoFe ₂O ₄ nanomagnets (SCFs) and typical ferromagnetic hysteresis. TiO ₂/SCFs showed larger specific surface area and better photocatalytic activities than TiO ₂and TiO ₂/CoFe ₂O ₄ photocatalysts prepared by the same method. The doping interaction between TiO ₂ and CoFe ₂O ₄ reduced thanks to the inert SiO ₂ mesosphere.