Fe3O4@UiO-66的制备及其对土霉素的吸附研究

    Preparation of Fe3O4@UiO-66 and Study on Its Adsorption of Oxytetracycline

    • 摘要: UiO-66作为最稳定的金属有机框架材料(metal-organic frameworks, MOFs)之一, 在吸附领域引起了广泛的关注。然而, UiO-66的使用仍然受到电子-空穴电荷分离能力弱或微孔可及性低的限制。研究采用乙酸对UiO-66构建介孔缺陷, 掺杂Fe3O4来制备Fe3O4@UiO-66。Fe3O4的掺杂使得UiO-66产生了变性中孔缺陷, 构建出对于四环素类抗生素具有优异吸附效果的结构。通过分析Fe3O4@UiO-66的晶体结构和理化性质变化, 研究Fe3O4@UiO-66对水中常见的抗生素土霉素(OTC)的吸附性能及机理。结果表明, Fe3O4@UiO-66对OTC的吸附量为201.72 mg·g-1, OTC的去除率为80.69%, 吸附过程符合拟二级动力学、Elovich和Langmuir等温吸附模型。吸附反应为吸热反应和熵增过程, 温度升高有利于吸附的进行, 吸附反应受pH值的影响较小。

       

      Abstract: As one of the most stable metal-organic frame materials (metal-organic frameworks, MOFs), UiO-66 has attracted extensive attention in the adsorption field. However, the use of UiO-66 is still limited by the weak electron-hole charge separation ability or the low accessibility of micropores. In this study, Fe3O4@UiO-66 was prepared by using acetic acid to construct the mesoporous defects of UiO-66 and doping Fe3O4. The doping of Fe3O4 results in the formation of denatured mesoporous defects in UiO-66, leading to good performance on adsorption of tetracycline antibiotics. Fe3O4@UiO-66 was used to adsorb and remove common oxytetracycline (OTC) from water. The adsorption properties and mechanism of Fe3O4@UiO-66 on OTC were studied by analyzing the crystal structure and physicochemical properties of Fe3O4@UiO-66. The results show that the adsorption capacity of Fe3O4@UiO-66 was 201.72 mg·g-1, and the removal rate of OTC was 80.69%. The adsorption process conforms to the pseudo-second-order kinetics, Elovich and Langmuir isothermal adsorption model. Adsorption reaction is endothermic reaction and with entropy increase process. The increase of temperature is beneficial to the adsorption. The adsorption reaction is less affected by pH.

       

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