Preparation and selective adsorption of organic pollutants by an inorganic molecular imprinted polymer

A novel inorganic molecular imprinted polymer (MIP) was synthesized by adding Al³⁺ to the Fe/SiO₂ gel with Acid Orange II (AO II) as the template. The MIP was characterized by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and nitrogen adsorption-desorption measurement. Compared with the non-imprinted polymer (NIP), the MIP enhanced the adsorption capacity of the target pollutants AO II. The selective adsorption capacity study indicated that the MIP adsorbed more AO II than the interferent Bisphenol A (BPA), which also has the structure of a benzene ring, thus proving the selective adsorption capacity of the MIP for template molecules AO II. In addition, the adsorption of AO II over MIP belonged to the Langmuir type and pseudo-second adsorption kinetics, and Dubinin-Radushkevich model indicates that the adsorption process of AO II over MIP and NIP are both given priority to chemical adsorption. The MIP reusability in performance was demonstrated in at least six repeated cycles.