Nitrogen-Doped Mesoporous Carbons Bearing Fe3O4 as Adsorbent for Effective Ag(I) Removal

Abstract

An efficient route is proposed to synthesize magnetic nitrogen-doped mesoporous carbon (Fe3O4/NMC) composites. The nitrogen-doped mesoporous carbon (NMC) material was prepared using a melamine–formaldehyde resin as nitrogen and carbon source and fumed silica as a template via a template method, and Fe3O4nanoparticles were introduced via an in situ formation method. The effects of the loading amount of Fe3O4on the morphology, structure, magnetic properties and adsorption performance of the Fe3O4/NMC composites were investigated. Fe3O4nanoparticles dispersed well on the surface and inside the NMC, and the Fe3O4/NMC remained a mesoporous structure. Fe3O4/NMC exhibited superparamagnetic behavior, and the maximum saturation magnetization was 30.1[Formula: see text]emu/g. Fe3O4/NMC had a decreased specific surface area and pore volume compared to NMC, but the Fe3O4/NMC composites still showed excellent adsorption capacity for Ag(I), reaching 71.9[Formula: see text]mg/g. The adsorption efficiency of Fe3O4/NMC remained at 90.3% of the initial removal capability after five cycles, which demonstrated the potential large-scale industrial applications of these composites.