The present work is focused on the hydrothermal fabrication of lanthanum (La)-based metal–organic frameworks (MOFs) with the linkers of benzene-1,4-dicarboxylic acid (BDC) and amine-functionalized BDC, namely, 2-aminobenzene-1,4-dicarboxylic acid (ABDC), which are abbreviated as La@BDC and La@ABDC, respectively. The developed La@BDC and La@ABDC MOF composites were utilized for defluoridation of water. The defluoridation capacities (DCs) of the La@BDC and La@ABDC MOF composites were found to be 4920 and 4950 mgF^– kg^–1, respectively. The influencing parameters of adsorption method, such as contact time, initial fluoride solution, MOF dosage, adsorbate pH, rivalry anions, and temperature, were investigated by batch scale. The structural and surface properties of the synthesized La@BDC and La@ABDC MOF composites were explored by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM) with selected area electron diffraction (SAED), energy-dispersive X-ray analysis (EDAX), and X-ray photoelectron spectroscopy (XPS). The best-fit model was found for both isotherms and kinetic studies for fluoride adsorption onto La-based MOF composites. Thermodynamic studies show the endothermic and spontaneous nature of fluoride adsorption onto the La@BDC and La@ABDC MOF composites. Furthermore, the La@BDC and La@ABDC MOF composites possess greater DCs even after six cycles in recyclability studies. Effective field study reports showed that the La@BDC and La@ABDC MOF composites are exceptionally encouraging and innovative type of adsorbent materials for defluoridation of contaminated field water.

中文翻译：

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氨基功能化苯-1,4-二羧酸制备的镧基金属有机骨架用于水脱氟的设计

目前的工作集中在水热法制备镧（La）基金属有机骨架（MOF），该骨架与苯-1,4-二羧酸（BDC）和胺官能化的BDC（2-氨基苯- 1,4-二羧酸（ABDC），分别缩写为La @ BDC和La @ ABDC。开发的La @ BDC和La @ ABDC MOF复合材料用于水的脱氟。La @ BDC和La @ ABDC MOF复合材料的脱氟能力（DCs）为4920和4950 mgF ^– kg ^–1， 分别。通过分批法研究了接触时间，初始氟化物溶液，MOF用量，吸附物pH，竞争性阴离子和温度等吸附方法的影响参数。通过粉末X射线衍射（PXRD），傅立叶变换红外光谱（FTIR），热重分析（TGA），Brunauer-Emmett-Teller（BET）研究了合成的La @ BDC和La @ ABDC MOF复合材料的结构和表面性能。分析，扫描电子显微镜（SEM），具有选定区域电子衍射（SAED）的透射电子显微镜（TEM），能量色散X射线分析（EDAX）和X射线光电子能谱（XPS）。找到了最合适的模型，用于等温线和动力学研究中，氟化物吸附在La基MOF复合材料上。热力学研究表明氟化物吸附在La @ BDC和La @ ABDC MOF复合材料上的吸热和自发性质。此外，即使在六个循环的可循环性研究中，La @ BDC和La @ ABDC MOF复合材料也具有更大的DC。有效的现场研究报告表明，La @ BDC和La @ ABDC MOF复合材料异常令人鼓舞，并且是用于污染现场水的脱氟的创新型吸附材料。