Tannin-based magnetic porous organic polymers as robust scavengers for methylene blue and lead ions

Abstract

Owing to the enormous threat from anthropogenic pollution in water resources, the importance of toxic contaminants treatments has become increasingly apparent. Porous organic polymers (POPs) are one kind of the most promising candidates as sorbents for the efficient removal of pollution. In the present study, tannin-based magnetic porous organic polymers (TA-MOPs) were fabricated through a rapid and scalable synthesis strategy by taking sustainable tannin acid as building blocks via azo coupling reaction without sacrificing any phenolic OH groups. The saturation magnetization of the TA-MOPs is tunable by controlling the amount of magnetic nanoparticles (MNPs) during the reaction process. Owing to its high special surface areas (110.7 m2 g−1) and abundant phenolic OH groups, the as-synthesized TA-MOPs presented ultrahigh adsorption capacities, and fast adsorption kinetic for the isolation of methylene blue (MB) and Pb2+ from aqueous solutions. The adsorption equilibrium reached within 10 min and max adsorption amounts were 1696 mg g−1 and 252 mg g−1 for MB and Pb2+, respectively. Moreover, its excellent stability and superparamagnetism enable its excellent cycle performance, which can be recycled 5 times without a significant decrease in performance, demonstrating the promise of TA-MOPs for green environmental governance.