摘要
通过自组装技术在CoFe2O4表面包裹分子筛MCM-48,合成了一种新型的"核/壳"结构磁性纳米复合材料CoFeM48.采用X射线衍射仪(XRD)、透射电子显微镜(TEM)、BET比表面积仪、振荡样品磁强计(VSM)等分别对CoFeM48的晶型、形貌、比表面积及磁性能等进行了系统表征分析.该复合材料对水中5种常见磺胺类抗生素表现出了良好的吸附性能,15℃时的平衡吸附量在68.9μg·g-1(磺胺二甲嘧啶)至99.6μg·g-1(磺胺甲二唑)之间.吸附过程符合准二级动力学模型,吸附等温线能用Freundlich模型拟合.热力学计算结果表明CoFeM48对磺胺类抗生素的吸附是以物理吸附为主的自发放热过程.红外结果表明氢键是CoFeM48表面官能团和磺胺之间的一个主要作用力.此外,分子筛外壳有序的二氧化硅结构和磺胺之间的π-π电子共轭作用也可能促进两者之间的吸附.
A novel ＂core/shell＂ structured magnetic nanocomposite, CoFeM48, was synthesized by coating the mesoporous material （MCM-48） on the surface of cobalt ferrite （CoFe2O4） using the self-assembly technology. The crystalline structure, morphology, specific surface area and magnetic properties of CoFeM48 were systematically characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, BET surface area measurement and vibrating sample magnetometer （VSM）, respectively. The synthesized nanocomposite exhibited good performance for the removal of five commonly-used sulfonamides （SAs） from water, with the maximum adsorption capacity ranging from 68.9 μg · g^-1 （for sulfamethazine） to 99.6 μg · g^-1 （for sulfamethizole） at 15 ℃. The adsorption kinetics of SAs onto CoFeM48 could be simulated by the pseudo-second-order model, and the adsorption isotherms could be expressed by Freundlich model. Thermodynamic calculations indicated that the adsorption of SAs onto CoFeM48 was a spontaneous exothermic physical process. Infrared spectra revealed that hydrogen bonding was one of the major interaction forces between the surface functional groups of CoFeM48 and SAs. In addition, the π-π conjugate interaction between the ordered silica structure of MCM-48 and SAs tended to promote the adsorption.
出处
《环境科学学报》
CAS
CSCD
北大核心
2013年第2期401-407,共7页
Acta Scientiae Circumstantiae
基金
国家自然科学基金项目(No.20837001)
国家高技术研究发展计划项目(No.2012AA062606)~~
关键词
磁性纳米复合材料
磺胺类抗生素
吸附
磁分离
水处理
magnetic nanocomposite
sulfonamides
adsorption
magnetic separation
water treatment
