Facile preparation of magnetic mesoporous MnFe2O4@SiO2-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 MnFe2O4@SiO2-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 MnFe2O4@SiO2-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 MnFe2O4nanoparticles, which ensured the easy separation by an external magnetic field. The performance of MnFe2O4@SiO2-CTAB composites in Cr(VI) removal was far better than that of bare MnFe2O4nanoparticles. There were two reasons for the effective removal of Cr(VI) by MnFe2O4@SiO2-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 MnFe2O4, followed by Cr(III) immobilized on MnFe2O4@SiO2-CTAB composites, which had been demonstrated by X-ray photoelectron spectroscopy results. The adsorption of Cr(VI) onto MnFe2O4@SiO2-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. MnFe2O4@SiO2-CTAB composites exhibited a great potential for the removal of Cr(VI) from water.
School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
Na
N
Li
School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China. Electronic address: fufenglian2006@163.com.
Fenglian
F
Fu
School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
Jianwei
J
Lu
School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
Zecong
Z
Ding
School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
Bing
B
Tang
School of Environmental Science and Engineering and Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China.
Jiabin
J
Pang
D000327:Adsorption; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D002857:Chromium / Q000032:analysis* / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry*; D008280:Magnetics; D017895:Manganese Compounds / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D012822:Silicon Dioxide / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
D002593:Cetrimonium Compounds; D005290:Ferric Compounds; D017895:Manganese Compounds; D014874:Water Pollutants, Chemical; C551151:manganese ferrite; D014867:Water; D002857:Chromium; C074702:chromium hexavalent ion; D012822:Silicon Dioxide; D000077286:Cetrimonium
Adsorption; Cr(VI) wastewater; MnFe(2)O(4)@SiO(2)−CTAB; Reduction