Decoration of Fe3+ on carboxyl microporous organic network to fabricate magnetic porous carbon for efficient adsorption and removal of cationic dyes

Abstract

Fabrication of novel magnetic porous materials for efficient magnetic adsorption and removal of environmental contaminants still remains great important and interesting in environmental science. Magnetic microporous organic networks (MONs) are a recent class of magnetic microporous materials highly potential in diverse areas. However, the strategies for the fabrication of magnetic MONs or MONs-derived magnetic adsorbents are still quite limited. To further develop novel method for the fabrication of MONs-derived magnetic adsorbents and to extend the application of MONs in environmental science, here we reported a convenient and new method by decorating Fe3+ on MON-2COOH to fabricate MON-derived magnetic porous carbon (MPC) for efficient adsorption and removal of cationic dyes from aqueous solution. The Fe3+ was firstly decorated on -COOH enriched MON-2COOH and then calcined to produce MPC under Ar atmosphere. The obtained MPC were well characterized and conducted to the adsorption of cationic dyes. The porous, negatively charged and unsaturated bond contained MPC gave extremely fast adsorption kinetics for cationic dyes via electrostatic, hydrogen bonding and π-π interactions. The adsorption of malachite green on MPC was fitted well with pseudo-second-order kinetic, Langmuir adsorption and monolayer adsorption models, and gave much faster adsorption kinetics and larger adsorption capacities than anionic dyes. Furthermore, the good superparamagnetic behavior and reusability made MPC could be easily recycled and reused. This work not only provided a new strategy to synthesis MON-derived MPC, but also possessed the potential of magnetic MONs-based adsorbents for the adsorption and removal of cationic dyes or trace contaminants in environment.

Keywords

• Microporous organic network
• Magnetic porous carbon
• Adsorption
• Cationic dye