Salicylidene Schiff Base Assembled with Mesoporous Silica SBA-15 for Cu (II) Removal in Aqueous Media

Abstract

Novel Schiff base-functionalized SBA-15 mesoporous silica is prepared, characterized and used as an adsorbent for heavy metal ion, Cu (II). The organic-inorganic hybrid mesoporous materials have been synthesized by two post-graftings of tetraethoxysilane (TEOS) with 3-aminopropyltrimethoxy-silane (APTES) and salicylaldehyde in sequence. The functionalized mesoporous materials are characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and nitrogen (N 2 ) adsorption-desorption analysis. The result indicates that, after sequent chemical modifications of aminopropyl and schiff base, the primary hexagonally ordered mesoporous structure of SBA-15 is not affected. The mesoporous silica, which has a BET surface area of 573.263 m 2 g -1 , a high pore diameter (centered at 5.24 nm) and pore volume of 0.847 cm3 g-1, exhibits the excellent adsorption capacity. The removal rate of Cu 2+ in aqueous media is high and the adsorbent can be regenerated by EDTA and acid treatments without changing its properties.