Abstract:
In this study, the removal effect of a new MOF-on MOF adsorbent based on Cu-Co bimetallic organic frameworks on tetracycline antibiotics (TCs) in water system was studied. The adsorbent (Cu-MOF@Co-MOF) were synthesized by solvothermal and self-assembly method at different concentrations of Co2+/Cu2+. The characterization results of SEM, XRD, XPS, FTIR and BET indicated that the MOF-on MOF structure of Cu-MOF@Co-MOF exhibited the best recombination and physicochemical properties when the molar ratio of Co2+: Cu2+ is 5:1. In addition, the Cu-MOF@Co-MOF have a high specific surface area and bimetallic clusters, which can achieve multi-target synergistic adsorption of TCs. Based on above advantages, Cu-MOF@Co-MOF provided a strong affinity and could efficiently adsorb more than 80% of pollutants in just 5 to 15 min using only 10 mg of the adsorbent. The adsorption capacity of tetracycline and doxycycline was 434.78 and 476.19 mg/g, respectively, showing satisfactory adsorption performance. The fitting results of the experimental data were more consistent with the Langmuir isotherm model and pseudo-second-order kinetic model, indicating that the adsorption process of TC and DOX occurred at the homogeneous adsorption site and was mainly controlled by chemisorption. Thermodynamic experiments showed that Cu-MOF@Co-MOF was thermodynamically advantageous for the removal of TCs, and the whole process was spontaneous. The excellent adsorption capacity and rapid adsorption kinetics indicate the prepared MOF-on MOF adsorbent can adsorb TCs economically and quickly, and have satisfactory application prospects for removing TCs in practical environments. The results of the study pave a new way for preparing novel MOFs-based water treatment materials with great potential for efficient removal.
摘要:
在这项研究中,研究了基于Cu-Co双金属有机骨架的新型MOF-onMOF吸附剂对水系统中四环素类抗生素(TCs)的去除效果。在不同浓度的Co2+/Cu2+下,采用溶剂热法和自组装法合成了吸附剂(Cu-MOF@Co-MOF)。SEM表征结果,XRD,XPS,FTIR和BET表明,当Co2:Cu2的摩尔比为5:1时,Cu-MOF@Co-MOF的MOF-onMOF结构表现出最佳的重组和理化性质。此外,Cu-MOF@Co-MOF具有较高的比表面积和双金属簇,可以实现TCs的多目标协同吸附。基于上述优点,Cu-MOF@Co-MOF具有很强的亲和力,仅使用10mg吸附剂即可在5至15分钟内有效吸附80%以上的污染物。四环素和强力霉素的吸附量分别为434.78和476.19mg/g,分别,表现出令人满意的吸附性能。实验数据的拟合结果与Langmuir等温线模型和伪二阶动力学模型较为一致,说明TC和DOX的吸附过程发生在均相吸附位点,主要受化学吸附控制。热力学实验表明,Cu-MOF@Co-MOF在热力学上有利于TCs的去除,整个过程是自发的。优异的吸附能力和快速的吸附动力学表明制备的MOF-onMOF吸附剂可以经济快速地吸附TCs,在实际环境中去除TC具有令人满意的应用前景。该研究结果为制备具有高效去除潜力的新型MOFs基水处理材料开辟了新途径。