Efficient Removal of Cd2+ by the Mesoporous Silica Functionalized by APTES

Amino-functionalized mesoporous silica (AFMS) with high amino loading, high surface area, and large pore size was synthesized using the anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as template and 3-aminopropyltriethoxysilane (APTES) as co-structure directing agent (CSDA). The synthesized AFMS was characterized by N₂ adsorption-desorption, TEM and elemental analyzer. The results of the removal of Cd²⁺ from aqueous solution showed that the pH value of aqueous solution affected the removal efficiency of Cd²⁺ greatly, and that unary adsorption isotherm of Cd²⁺ on the AFMS was well described by the Sips isotherm model, in which the adsorption capacity was 2.43 mmol/g for Cd²⁺, much higher than the literature data.