Synthesis of N-Doped Magnetic Mesoporous Carbon Composites for Adsorption of Ag(I) in Aqueous Solution.

In this work, a novel N-doped magnetic mesoporous carbon (NMC) composite (Fe₃O₄/NMC) was synthesized by a two-step process. First, NMC was prepared by a template method using a melamine formaldehyde resin as nitrogen and carbon sources, and then, Fe₃O₄ nanoparticles were loaded into the as-prepared NMC via coprecipitation process. The morphology, structure, and magnetic properties of Fe₃O₄/NMC were characterized and its adsorption properties were investigated. It can be found that Fe₃O₄/NMC with saturation magnetization of 20 emu · g features a mesoporous structure, and its specific surface area reaches 513 m² · g. These two excellent specificities are propitious to the adsorption and separation of Ag(I) from aqueous solution. The adsorption behavior of Fe₃O₄/NMC nanocomposite has been investigated by adsorption kinetics and isotherms adsorption analyses as well. The adsorption isotherm and the adsorption kinetics of Ag(I) onto Fe₃O₄/NMC agrees well with Langmuir model and pseudo-second-order model, respectively. Moreover, the Fe₃O₄/NMC was easily to recovery by applied magnetic field, the adsorption capacity of Fe₃O₄/NMC was about 90.3% of the initial saturation adsorption capacity after five continuous uses.