Superfast removal of dyes and herbicides with triphenylamine-based porous organic polymers by one-step sulfonation and carboxylation

The water pollution caused by modern chemical industries has become one of the most severe global environmental challenges, as an effective approach, the development of cost-effective adsorbents with rapid removal efficiency is of great significance. Herein, a simple and cost-effective post-modification synthetic strategy that includes sulfonation and carboxylation for the synthesis of porous organic polymer (POP-SO3H) was proposed, which endows POP-SO3H ultrafast adsorption rates, high adsorption capacity, and excellent reusability. For cationic dyes and herbicides including methylene blue (MB), rhodamine B (RhB), paraquat, and diquat, the removal efficiencies of POP-SO3H all reached > 96 % in only 10 s interaction and reached equilibrium within 30 s. The uptake kinetics of MB, RhB, paraquat, and diquat are 17.29, 16.12, 25.14, and 60.96 g mg−1 min−1, respectively, outperforming most of the previously reported adsorbents. Moreover, the removal efficiencies of flow-through experiments towards MB and RhB still remained > 99 % even at the flow rate of 14.7 mL min−1. This study provides a 'one stone with two birds' post-functionalization strategy for the preparation of cost-effective anionic adsorbents with superfast removal kinetics toward cationic pollutants.