Preparation of TiO2/Silicalite-2@CoFe2O4 Magnetic Composites and Evaluation of their Photocatalytic Activity in Cr(VI) Removal
2015
Lu, Mang | Cheng, Yue | Pan, Shun-long | Yang, Ting-ling | Zhang, Zhong-zhi
Magnetic nanoparticles of CoFe₂O₄ were synthesized by co-precipitation method. The magnetic material silicalite-2@CoFe₂O₄ (SC) was prepared by using tetrabutylammonium hydroxide as the template, tetraethoxysilane as the silica source and CoFe₂O₄ as the magnetic core. TiO₂/silicalite-2@CoFe₂O₄ (TSC) magnetic photocatalyst was prepared by sol-gel technique using SC particles as the supporter and tetrabutyltitanate as the titanium source. The samples were characterized by X-ray diffraction, scanning electron microscopy, N₂ adsorption-desorption, Fourier transform infrared spectroscopy, and ultraviolet (UV)–visible diffuse reflectance spectra. The reduction of Cr(VI) in aqueous solution by UV/TSC process was studied under various operating conditions. The results demonstrate that the as-synthesized TSC has high photocatalytic activity due to the high dispensability of TiO₂ provided by silicalite-2@CoFe₂O₄. The removal of Cr(VI) reached 72.9 % by using 0.6 g/L of TSC under the optimum conditions within 180 min. The photocatalytic reduction of Cr(VI) by TSC followed the Langmuir–Hinshelwood kinetic model. At the end of the reaction, TSC could easily be recovered and could be reused without the significant loss of the catalytic activity.
显示更多 [+] 显示较少 [-]