Synthesis of a novel mesoporous Fe 3 O 4 @SiO 2 /CTAB-SiO 2 composite material and its application in the efficient removal of bisphenol A from water

In this study, a novel mesoporous magnetic composite material (Fe3O4@SiO2/CTAB-SiO2) was prepared by a sol-gel and etching method. The morphology, composition, structure, and magnetic properties of the mesoporous Fe3O4@SiO2/CTAB-SiO2 composite material were characterized, and the feasibility of using it to remove bisphenol A (BPA) from water was studied. The results showed that under the optimal adsorption conditions, the removal efficiency of BPA by the composite material is 93.2%. Also, the adsorption isotherms and adsorption kinetic studies showed that the Freundlich isotherm model and the pseudo-second-order kinetic model could better describe the equilibrium and kinetic behaviors of the adsorption process. The maximum adsorption capacity of the composite material for the adsorption of BPA was evaluated as 208.3 mg/g, which was a remarkable amount. The thermodynamic study indicated that the adsorption process was chemical, spontaneous, and exothermic, and the main interaction mechanisms with BPA might be electrostatic and hydrophobic interactions. In addition, after 6 cycles of adsorption-desorption, the recovery efficiency was 80.5% and the FTIR, XRD, and TEM tests showed that the overall structure of the composite material was relatively stable, and the results of real sample verification show that the recovery rate of different added BPA concentration (10, 30, and 50 μg/L) was above 90%. In summary, this composite material is a promising effective magnetic adsorbent for removing bisphenols.