Facile preparation of magnetic mesoporous MnFe 2 O 4 @SiO 2 -CTAB composites for Cr(VI) adsorption and reduction

Chromium-contaminated water is regarded as one of the biggest threats to human health. In this study, a novel magnetic mesoporous MnFe O @SiO -CTAB composite was prepared by a facile one-step modification method and applied to remove Cr(VI). X-ray diffraction, scanning electron microscopy, transmiss...

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Bibliographic Details
Published in:Environmental pollution (1987) 2017-01, Vol.220 (Pt B), p.1376
Main Authors: Li, Na, Fu, Fenglian, Lu, Jianwei, Ding, Zecong, Tang, Bing, Pang, Jiabin
Format: Article
Language:English
Subjects:
Adsorption
Cetrimonium Compounds - chemistry
Chromium - analysis
Chromium - chemistry
Ferric Compounds - chemistry
Magnetics
Manganese Compounds - chemistry
Microscopy, Electron, Scanning
Microscopy, Electron, Transmission
Nanoparticles - chemistry
Photoelectron Spectroscopy
Silicon Dioxide - chemistry
Water - chemistry
Water Pollutants, Chemical - analysis
Water Pollutants, Chemical - chemistry
Water Purification - methods
X-Ray Diffraction
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Summary:Chromium-contaminated water is regarded as one of the biggest threats to human health. In this study, a novel magnetic mesoporous MnFe O @SiO -CTAB composite was prepared by a facile one-step modification method and applied to remove Cr(VI). X-ray diffraction, scanning electron microscopy, transmission electron microscopy, specific surface area, and vibrating sample magnetometer were used to characterize MnFe O @SiO -CTAB composites. The morphology analysis showed that the composites displayed a core-shell structure. The outer shell was mesoporous silica with CTAB and the core was MnFe O nanoparticles, which ensured the easy separation by an external magnetic field. The performance of MnFe O @SiO -CTAB composites in Cr(VI) removal was far better than that of bare MnFe O nanoparticles. There were two reasons for the effective removal of Cr(VI) by MnFe O @SiO -CTAB composites: (1) mesoporous silica shell with abundant CTA significantly enhanced the Cr(VI) adsorption capacity of the composites; (2) a portion of Cr(VI) was reduced to less toxic Cr(III) by MnFe O , followed by Cr(III) immobilized on MnFe O @SiO -CTAB composites, which had been demonstrated by X-ray photoelectron spectroscopy results. The adsorption of Cr(VI) onto MnFe O @SiO -CTAB followed the Freundlich isotherm model and pseudo-second-order model. Tests on the regeneration and reuse of the composites were performed. The removal efficiency of Cr(VI) still retained 92.4% in the sixth cycle. MnFe O @SiO -CTAB composites exhibited a great potential for the removal of Cr(VI) from water.
ISSN:1873-6424