Property Variation of Magnetic Mesoporous Carbon Modified by Aminated Hollow Magnetic Nanospheres: Synthesis, Characterization, and Sorption

Magnetic mesoporous carbon with particular morphologies was fabricated by immobilizing uniform aminated hollow magnetic nanospheres (AHMNs) in an oxidized mesoporous carbon (OC) matrix with different mass ratios (AHMOC-Y, Y = 1:1, 2:1, 5:1). This study was devoted to exploring the effects on morphology, surface charge, and adsorption capacity when AHMNs were immobilized onto OC. The morphology and surface properties were studied using SEM, BET, XRD, FTIR, XPS, and VSM. Batch experiments were carried out to study the sorption behavior of methylene blue by AHMOC-Ys, indicating that a good adsorption capacity of cation dye could be obtained at mild conditions (at pH = 8 compared with pH = 11), which was consistent to the point of zero charge (pH(pzc)). Characterization of the adsorption behavior revealed that kinetics and isotherm synthesis were well-fitted respectively by the pseudo-second-order model and the Freundlich isotherm model. The rate-limiting step mainly involved film diffusion and intraparticle diffusion for the whole reaction. Thermodynamic analysis indicated that the adsorption reaction was an endothermic and spontaneous process. The conclusion reveals that AHMOC-2:1 has advantages in terms of adsorption capacity and separation feasibility compared with OC, AHMOC-1:1, and AHMOC-5:1, which could make it preferable in practical applications for environmental purification.