In this work, Schiff base network-1 (SNW-1), as a new generation of covalent organic frameworks (COFs), was synthesized and modified by fabrication of a composite with clay mineral montomorillonite (Mt). It was used for simultaneous removal of anionic and cationic dyes from aqueous solutions. The fabricated composite was characterized successfully with various techniques. Tartrazine (TT) and methylene blue (MB) were selected as model anionic and cationic dyes, respectively. The effects of the percentage of each component in the composite, initial pH, and initial dye concentration were evaluated on the adsorption capacity. Adsorption reaction models and adsorption diffusion models were used to study the kinetic process of adsorption. Adsorption of both dyes reached equilibrium after 40 min. The obtained results were fitted to Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) models to predict the isotherms of adsorption. Under optimum conditions for removal of each dye with the composite, the maximum adsorption capacity of 519.2 and 602.7 mg g⁻¹ were obtained for TT and MB, respectively. The used SNW-1/Mt composite could be regenerated by salty methanol. The high adsorption capacity and excellent reusability make SNW-1/Mt composite attractive for the simultaneous removal of anionic and cationic dyes from aqueous solutions.

Graphical abstract

中文翻译：

---

共价有机骨架和蒙脱石纳米复合材料作为高级吸附剂：合成、表征和同时吸附阳离子和阴离子染料的应用

在这项工作中，希夫碱网络-1（SNW-1）作为新一代共价有机骨架（COFs），通过与粘土矿物蒙脱石（Mt）的复合材料制备和改性。它用于同时去除水溶液中的阴离子和阳离子染料。用各种技术成功地表征了制造的复合材料。分别选择柠檬黄 (TT) 和亚甲蓝 (MB) 作为模型阴离子和阳离子染料。评估了复合材料中每种组分的百分比、初始 pH 值和初始染料浓度对吸附能力的影响。吸附反应模型和吸附扩散模型被用来研究吸附的动力学过程。40 分钟后两种染料的吸附达到平衡。所得结果拟合到 Langmuir、Freundlich、Temkin 和 Dubinin-Radushkevich (DR) 模型来预测吸附等温线。在复合去除每种染料的最佳条件下，最大吸附量分别为519.2和602.7 mg·g分别为 TT 和 MB 获得了^-1。使用过的 SNW-1/Mt 复合材料可以通过含盐甲醇进行再生。高吸附能力和出色的可重复使用性使 SNW-1/Mt 复合材料在同时去除水溶液中的阴离子和阳离子染料方面具有吸引力。

图形概要