功能化有序介孔碳对重金属离子Cu(Ⅱ)、Cr(Ⅵ)的选择性吸附行为

Selective Adsorption Behavior of Cu(Ⅱ) and Cr(Ⅵ) Heavy Metal Ions by Functionalized Ordered Mesoporous Carbon

以三嵌段共聚物F127为模板剂,酚醛树脂为碳源,正硅酸乙酯为硅源,三组分共组装合成介孔碳-氧化硅纳米复合物,再经HF去除氧化硅,得到有序介孔碳(OMC).X射线衍射(XRD)、透射电子显微镜(TEM)、低温N2吸脱附(BET)等测试表明,所得样品具有高度有序的介孔结构,比表面积和孔容分别为1330m2·g-1和2.13cm3·g-1,平均孔径6.4nm.对其先氧化、后氯化、再胺化,得到不同胺基接枝量的胺化介孔碳(C-NH2(m),m为加入的乙二胺的质量(g)).傅里叶变换红外(FT-IR)光谱表征结果证实,胺基官能团成功接枝到有序介孔碳表面.TEM测试表明介孔碳的有序孔道结构得到了较好的保持.以有序介孔碳、胺化介孔碳作吸附剂对Cu(Ⅱ)、Cr(Ⅵ)进行选择性吸附研究.结果表明:功能化修饰前,样品对Cu(Ⅱ)、Cr(Ⅵ)饱和吸附量分别为213.33、241.55mg·g-1;修饰后饱和吸附量可分别达到495.05、68.21mg·g-1.功能化介孔碳表现了较强的选择性吸附Cu(Ⅱ)的能力.

An ordered mesoporous carbon silica nanocomposite was synthesized by the evaporation induced triconstituent co assembly method, wherein a soluble resol polymer was used as an organic precursor, tetraethoxysilane was used as an inorganic precursor, and the triblock copolymer F127 was used as the template. After the removal of silica with HF, ordered mesoporous pure carbon （OMC） was obtained. X ray diffraction （XRD）, N2 adsorption desorption isotherms （BET）, and transmission electron microscopy （TEM） showed that the OMC product had a highly ordered structure with a large pore size of 6.4 nm, a pore volume of 2.13 cm3·g-1, and a high surface area of 1330 m2·g-1. The OMC was subsequently functionalized with ethylenediamine by treatment with nitric acid and thionyl chloride to obtain a functionalized ordered mesoporous carbon （C NH2（m））, m is the mass （g） of the added ethylenediamine. Fourier transform infrared （FTIR） spectroscopy showed that the amino group was successfully grafted onto the surface of the OMC. TEM images showed that C NH2（m） had a highly ordered mesoporous structure. OMC and C NH2（m） were used as adsorbents for the selective adsorption of Cu（Ⅱ） and Cr（Ⅵ） ions from the aqueous solution. C NH2（9.0） had a higher adsorption capacity for Cu（Ⅱ） of 495.05 mg·g-1 versus 213.33 mg·g-1 for the OMC and a lower adsorption capacity for Cr（Ⅵ） of 68.21 mg·g-1 versus 241.55 mg·g-1 for the OMC, indicating its significantly favorable potential for the selective adsorption of Cu（Ⅱ）.