Abstract Water-resistant magnetic graphene-anchored zeolite imidazolate (Fe3O4/ZIF-8-G) composite materials with the largest surface area are formed by directly growing a hydrophobic ZIF-8 skeleton onto a graphene support through self-assembly in methanol. Fe3O4/ZIF-8-G hybrid composite has water resistance and super strong adsorption capacity, and is used as an effective adsorbent for adsorption and removal of residual tetracycline in wastewater. The morphologies and structure, as well as water resistance of Fe3O4/ZIF-8-G, were characterized using FT-IR, XRD, SEM, TEM, TGA, N2 adsorption and pHPZC. The adsorption for tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) followed pseudo-second-order kinetics and fitted the Freundlich adsorption model with the simultaneous adsorption capacity for TC (382.58 mg g−1), OTC (565.94 mg g−1) and CTC (608.06 mg g−1) at pH 5–6 for 10 h. These were much higher than previously reported results for the removal of tetracycline from aqueous solutions. The used Fe3O4/ZIF-8-G could be effectively reused and recycled at least five times without significant loss of adsorption capacity. The hydrophobic and π-π interaction between the aromatic rings of TCs and the aromatic imidazole rings of the ZIF-8-G framework were the main adsorption mechanism on the surface of Fe3O4/ZIF-8-G. Constructing a hydrophobic surface of ZIF-8/G framework resulted in a reduction of the hydrophilic sites of the surface. This can improve stability and selective adsorption of ZIF-8-G framework. In addition, the results show no significant difference in the adsorption kinetics and adsorption capacity of Fe3O4/ZIF-8-G for TC, OTC and CTC in pure water and wastewater.

中文翻译：

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一种耐水磁性石墨烯锚定沸石咪唑酯框架，用于有效吸附和去除废水中残留的四环素

摘要通过在甲醇中自组装在石墨烯载体上直接生长疏水性 ZIF-8 骨架，形成具有最大表面积的防水磁性石墨烯锚定沸石咪唑酯（Fe3O4/ZIF-8-G）复合材料。Fe3O4/ZIF-8-G杂化复合材料具有耐水性和超强吸附能力，用作吸附去除废水中残留四环素的有效吸附剂。利用 FT-IR、XRD、SEM、TEM、TGA、N2 吸附和 pHPZC 对 Fe3O4/ZIF-8-G 的形貌、结构以及耐水性进行了表征。对四环素（TC）、土霉素（OTC）和金霉素（CTC）的吸附遵循准二级动力学，并拟合Freundlich吸附模型，同时对TC（382.58 mg g−1）、OTC（565.94 mg g-1）的吸附容量−1) 和 CTC (608.06 mg g−1)，pH 5–6 10 小时。这些结果远高于之前报道的从水溶液中去除四环素的结果。使用过的Fe3O4/ZIF-8-G可以有效地重复使用和回收至少五次，而不会显着损失吸附能力。TCs的芳香环与ZIF-8-G骨架的芳香咪唑环之间的疏水性和π-π相互作用是Fe3O4/ZIF-8-G表面的主要吸附机制。构建ZIF-8/G框架的疏水表面导致表面亲水位点的减少。这可以提高ZIF-8-G框架的稳定性和选择性吸附。此外，结果表明Fe3O4/ZIF-8-G对纯水和废水中TC、OTC和CTC的吸附动力学和吸附能力没有显着差异。