Facile Synthesis of Magnetic Nitrogen-Doped Porous Carbon from Bimetallic Metal–Organic Frameworks for Efficient Norfloxacin Removal

Abstract

Magnetic nitrogen-doped porous carbon (MNPC) has been prepared via self-catalytic pyrolysis of bimetallic metal-organic frameworks (MOFs). The as-obtained MNPC showed favorable features for antibiotics adsorption such as high specific surface area (871 m2 g−1), high pore volume (0.75 cm3 g−1), porous structure, good graphitization degree, and rich N-doping. Moreover, the MNPC has magnetic properties due to the Co species, which is embedded with a high dispersion, so the absorbent can be easily separated. Based on the above excellent characteristics, the MNPC was used as the absorbent for norfloxacin (NOR) removal. The experimental maximum NOR adsorption capacity of MNPC was 55.12 mg g−1 at 298.15 K and a pH of 6.0 with an initial NOR concentration of 50 mg L−1. The data analysis of the kinetics revealed that the experimental data of NOR uptakes versus time agreed with the pseudo-second order model. The isotherm data analysis revealed the favorable application of the Freundlich model. Based on the adsorption results over a wide range of conditions, the dominant adsorption mechanisms were found to be pore-filling, electrostatic interaction, and the H-bond.

Keywords

• self-catalytic pyrolysis
• porous carbon
• metal–organic frameworks
• antibiotics
• adsorption