Liu Yi, Huang Yumin, Xiao Aiping, Qiu Huajiao, Liu Liangliang
Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China.
Nanomaterials (Basel). 2019 Jan 2;9(1):51. doi: 10.3390/nano9010051.
Metal-organic frameworks (MOFs) are considered as good materials for the adsorption of many environmental pollutants. In this study, magnetic Fe₃O₄/MIL-88A composite was prepared by modification of MIL-88A with magnetic nanoparticles using the coprecipitation method. The structures and magnetic property of magnetic Fe₃O₄/MIL-88A composite were characterized and the adsorption behavior and mechanism for Bromophenol Blue (BPB) were evaluated. The results showed that magnetic Fe₃O₄/MIL-88A composite maintained a hexagonal rod-like structure and has good magnetic responsibility for magnetic separation (the maximum saturation magnetization was 49.8 emu/g). Moreover, the maximum adsorption amount of Fe₃O₄/MIL-88A composite for BPB was 167.2 mg/g and could maintain 94% of the initial adsorption amount after five cycles. The pseudo-second order kinetics and Langmuir isotherm models mostly fitted to the adsorption for BPB suggesting that chemisorption is the rate-limiting step for this monomolecular-layer adsorption. The adsorption capacity for another eight dyes (Bromocresol Green, Brilliant Green, Brilliant Crocein, Amaranth, Fuchsin Basic, Safranine T, Malachite Green and Methyl Red) were also conducted and the magnetic Fe₃O₄/MIL-88A composite showed good adsorption for dyes with sulfonyl groups. In conclusion, magnetic Fe₃O₄/MIL-88A composite could be a promising adsorbent and shows great potential for the removal of anionic dyes containing sulfonyl groups.
金属有机框架材料（MOFs）被认为是吸附多种环境污染物的优良材料。在本研究中，采用共沉淀法通过用磁性纳米颗粒修饰MIL-88A制备了磁性Fe₃O₄/MIL-88A复合材料。对磁性Fe₃O₄/MIL-88A复合材料的结构和磁性进行了表征，并评估了其对溴酚蓝（BPB）的吸附行为及吸附机理。结果表明，磁性Fe₃O₄/MIL-88A复合材料保持六方棒状结构，对磁分离具有良好的磁响应性（最大饱和磁化强度为49.8 emu/g）。此外，Fe₃O₄/MIL-88A复合材料对BPB的最大吸附量为167.2 mg/g，经过五次循环后可保持初始吸附量的94%。准二级动力学和朗缪尔等温线模型最能拟合BPB的吸附，表明化学吸附是这种单分子层吸附的限速步骤。还研究了该复合材料对另外八种染料（溴甲酚绿、亮绿、亮藏花红、苋菜红、碱性品红、番红T、孔雀石绿和甲基红）的吸附能力，磁性Fe₃O₄/MIL-88A复合材料对含磺酰基的染料表现出良好的吸附性能。总之，磁性Fe₃O₄/MIL-88A复合材料可能是一种有前景的吸附剂，在去除含磺酰基的阴离子染料方面具有巨大潜力。
