摘要
采用常温搅拌法,在聚苯乙烯磺酸钠(PSS)处理过的Fe_3O_4表面诱导生长ZIF-8壳层,成功合成了磁性核壳金属有机骨架Fe_3O_4@ZIF-8,并对其吸附去除偶氮染料刚果红的性能进行了探究,考察了刚果红初始浓度和接触时间、Fe_3O_4@ZIF-8投加量以及pH对刚果红去除的影响。SEM、TEM、XRD、FT-IR及VSM表征结果证明,ZIF-8纳米颗粒已成功负载于Fe_3O_4表面,形成了典型的核壳结构,并且具有优异的磁学性能。吸附实验结果表明,反应最佳pH为6,吸附剂投加量为500 mg·L~(-1);当反应时间达到180 min时,吸附达到平衡。吸附反应的吸附动力学和吸附等温线分析表明,刚果红染料在Fe_3O_4@ZIF-8上的吸附动力学符合二级动力学方程,吸附等温线符合Langmuir模型。Fe_3O_4@ZIF-8吸附剂对刚果红具有高效的选择吸附性能并且在循环吸附中展现出良好的循环吸附性能。因此,磁性核壳金属有机骨架Fe_3O_4@ZIF-8作为吸附剂在去除刚果红染料方面有着广阔的应用前景。
The magnetic core-shell metal organic framework Fe_3O_4@ZIF-8 was successfully synthesized by treating the surface of Fe_3O_4 with sodium polystyrene sulfonate(PSS) and inducing ZIF-8 shell growth on it under continuous stirring at room temperature. The performance of adsorption and removal of azo dye congo red by Fe_3O_4@ZIF-8 was investigated. The effects of initial concentration and contact time, Fe_3O_4@ZIF-8 dosage and pH on congo red removal were investigated. The characterization of SEM, TEM, XRD, FT-IR and VSM showed that ZIF-8 nanoparticles have been successfully loaded on the surface of Fe_3O_4 to form a typical coreshell structure with excellent magnetic properties. The experimental results showed that the optimum pH was 6,the dosage of adsorbent was 500 mg·L~(-1), and the adsorption equilibrium was achieved at the reaction time of180 min. The adsorption kinetics of congo red on Fe_3O_4@ZIF-8 was in accordance with the second-order kinetic equation, and the adsorption isotherm followed Langmuir model. Fe_3O_4@ZIF-8 adsorbent had high selective adsorption performance for congo red and presented good reusability in cyclic adsorption. Therefore, magnetic core-shell metal-organic framework Fe_3O_4@ZIF-8 had broad application prospects in the removal of congo red dyes as adsorbent.
引文
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