Preparation of FeBTC/silica aerogels by a co-sol-gel process for organic pollutant adsorption

In this paper, a series of FeBTC/silica hybrid aerogels (FeBTC-SA) have been successfully prepared by a facile method. Specifically, Fe (III) metal salts were added to a silica (SiO₂) sol containing trimesic acid (H₃BTC) at room temperature for co-sol gelation and then CO₂ supercritical drying was introduced to obtain FeBTC/SiO₂ hybrid aerogels. The composites have been completely characterized by FT-IR, SEM, elemental analysis and HR-TEM analysis techniques. Meanwhile, adsorption properties of hybrid aerogels have also been systematically investigated through a typical organic dye methyl blue (MB). The results show that all the as-synthesized FeBTC-SA composites have a three-dimensional porous network structure. The TEM analysis further shows that the composite is a semi-crystal, while the FeBTC particles are crystalline of MIL-100(Fe). Furthermore, with the increase of FeBTC content, MB adsorption performance of composites is increasingly improved. By the elaborately manipulating the π–π interactions between MB and the benzene rings of FeBTC/SiO₂ hybrid aerogels, the static adsorption efficiency of FeBTC-SA (3:50) (molar ratio of Fe:Si = 3:50) can be quickly reached at 99.1%, which is increased by 11% compared to the pure SiO₂ aerogels. Therefore, It provides a new avenue for the important applications of hybrid aerogels as highly efficient adsorbents in water purification. (paper)