The development of ionic porous organic polymer (POPs) for the efficient removal of charged organic pollutants is of paramount significance. Herein, in this work, a 2D conjugated POP based on tetraphenyl ethylene moiety was firstly synthesized, and then it was further cross-linked to prepare a building block via the Friedel-Crafts alkylation reaction and “knitting” method. Two functional groups with opposite charges including the cationic quaternary ammonium group and anionic sulfonate group have been subsequently introduced to synthesize 3D ionic POPs named TCN-7 and TCN-8 under mild conditions to improve the hydrophilicity and enhance the adsorption affinity (primarily electrostatic interaction). Although the surface areas have decreased after post-modification, they still exhibited improved adsorption performance toward diverse charged organic dyes and herbicides. Especially for an anionic dye congo red (CR) and a cationic dye methylene blue (MB), TCN-7 and TCN-8 showed a removal efficiency > 99.5 % within a contact time of merely 1 min, respectively. Moreover, TCN-7 displayed an adsorption capacity of 2246 and 386 mg/g for CR and an anionic herbicide 2,4-dichlorophenoxyacetic acid, and TCN-8 reaches 1984 and 327 mg/g for MB and a cationic herbicide paraquat, which has surpassed the as-prepared 2D POPs and most of the recently reported adsorbents. More importantly, they exhibited excellent stability after five cycles and superfast removal ability in the column adsorption experiments, demonstrating potential application in real wastewater treatment scenarios. Our work may provide a platform to develop 3D ionic POPs via a post-modification strategy in one step under mild conditions, which is promising in the efficient removal of charged organic pollutants.

中文翻译：

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构建通过后改性策略开发 3D 离子多孔有机聚合物的平台，以高效吸附带电有机污染物


开发用于有效去除带电有机污染物的离子多孔有机聚合物 （POP） 具有至关重要的意义。在此，在这项工作中，首先合成了基于四苯乙烯部分的 2D 共轭 POP，然后通过 Friedel-Crafts 烷基化反应和 “编织” 方法进一步交联以制备结构单元。随后引入了两个带相反电荷的官能团，包括阳离子季铵基团和阴离子磺酸盐基团，在温和条件下合成名为 TCN-7 和 TCN-8 的 3D 离子 POP，以提高亲水性并增强吸附亲和力（主要是静电相互作用）。尽管后改性后表面积有所减少，但它们对各种带电有机染料和除草剂的吸附性能仍然有所改善。特别是对于阴离子染料刚果红 （CR） 和阳离子染料亚甲蓝 （MB），TCN-7 和 TCN-8 在短短 1 分钟接触时间内的去除效率分别为 99.5 %，> 1 分钟。此外，TCN-7 对 CR 和阴离子除草剂 2,4-二氯苯氧乙酸的吸附容量分别为 2246 和 386 mg/g，TCN-8 对 MB 和阳离子除草剂百草枯的吸附容量达到 1984 和 327 mg/g，超过了现有制备的 2D POPs 和大多数最近报道的吸附剂。更重要的是，它们在 5 次循环后表现出优异的稳定性和超快的去除能力，在实际废水处理场景中显示出潜在的应用。我们的工作可能提供一个平台，在温和的条件下通过后改性策略一步开发 3D 离子 POP，这在有效去除带电有机污染物方面很有希望。