Preparation and characterization of organic-functionalized mesoporous silica as heavy metal adsorbents

Novel organic-inorganic hybrid mesoporous materials have attracted much attention because the functional organic groups can bring these materials special properties, such as selective absorption and new catalytic properties. In this paper, two kind of bis(triethoxysilyl) organic skeleton (EtO)3Si-(CH2)3-NH-C(O)-X-C(O)-NH-(CH2)3-Si(OEt)3 (X = 1,4-benzene (BSPB), 2,5-thienyl (BSPT)) precursors were synthesized firstly. Then bridged organic-inorganic hybrid mesoporous materials were prepared by direct grafting on MCM-41. The MCM-41 was obtained under basic conditions using cetyltrimethylammonium bromide (CTAB) as a template with tetraethyl orthosilicate. FT-IR spectra showed the acylamino, carbonyl, phenyl and thienyl groups had been introduced into the materials. The structures of these materials were further confirmed by X-ray diffraction (XRD) and the N2 adsorption-desorption. In addition, the adsorption capacity of heavy metal ions such as mercury, cadmium, and lead, was evaluated. The results indicated that the functionalized mesoporous materials with high porosity and specific surface area were successfully prepared, and the new prepared materials exhibited good adsorption capacity for heavy metal ions Hg2+, Cd2+, and Pb2+.