Highly magnetically responsive porous nanoparticles based on tris(β-keto-hydrazo)-cyclohexane subunit: Fast removal of dyes from water with convenient recyclability

Porous organic polymers with magnetic responsibility have been developed for removal of hazardous substances from water, and attracted much attention. However, the technique to incorporate the polymers and magnetic particles well to give the composite as a whole remained challenging, as well as ultrafast adsorption and convenient recycling. In this paper, the tris(β-keto-hydrazo)-cyclohexane-based highly magnetically responsive porous magnetic nanoparticles (Fe3O4 @TKH-POPs) have been synthesized via a one-pot azo coupling reaction in water with the Fe3O4 magnetic nanoparticles as templates. And the resulted Fe3O4 @TKH-POPs showed very fast removal of organic dye pollutants such as methylene blue (MB) and acid red-18 (AR-18) from water, requiring less than 1 min to reach adsorption equilibrium. Additionally, the superparamagnetism of Fe3O4 @TKH-POPs made the separation and recovery very convenient, and their stability lead to good reusability, i. e., no any loss of adsorption capacity after 5 recycles. This work represented successful examples to design of magnetically responsive porous organic polymers of novel structure with irreversible tautomerization