Facile microwave-assisted production of Fe3O4 decorated porous melamine-based covalent organic framework for highly selective removal of Hg2+

Well dispersed magnetic Fe3O4 decorated porous melamine-based covalent organic frameworks (M-COFs) were facilely fabricated through a microwave-assisted process. The result showed that magnetic M-COFs possess large surface areas of 344-600 m(2) g(-1) and good magnetic separation performance (M-S = 0.75-3.59 emu g(-1)). Adsorption properties were preliminarily tested by the adsorptive removal of heavy metal ions from waste water. Remarkably, the as-synthesized Fe3O4/M-COFs display highly selective adsorption of Hg2+ with high adsorption capacity (97.65 mg g(-1)). This highly selective removal of Hg2+ was caused by the high density of N group in M-COFs. In addition, this selective adsorption of Hg2+ was not interfered with other metal ions such as Na+, Cd2+, Zn2+, Ni2+, Pb2+, Mg2+ and Cr3+.