In this paper, we exploit our prior successful synthesis of MOF-199 single crystals using the reaction-diffusion framework (RDF), to synthesize multivariate metal-organic frameworks (MTV-MOFs) version with enhanced properties. The MTV-MOFs are synthesized by creating defects within the MOF-199 crystal structure by integrating organic linkers entailing different functional groups. Accordingly, 5-aminoisophthalic acid (NH₂-BDC) and 5-hydroxyisophthalic acid (OH-BDC) are separately mixed with 1,3,5-benzenetricarboxylic acid (BTC) in three different starting ratios of X-BDC:BTC (1:3, 1:1) and 3:1). The effects of this linker on the morphology of the synthesized MTV-MOFs, their thermal stability, and their surface area are investigated. The extent of the incorporation of the linkers in the framework is elucidated via ¹H-NMR spectroscopy and it is shown that the incorporation varies as a function of the location along the tubular reactor, a characteristic of RDF. The enhanced properties of the synthesized MTV-MOFs are further demonstrated by measuring its adsorptive capability for methylene blue (MB) and rhodamine B (Rh B) in aqueous solution, and compared with that of the as-synthesized MOF-199. The kinetic and thermodynamic studies reveal that MTV-MOFs with the ratio of X-BDC:BTC (1:1) exhibit the best uptakes of MB (263 mg/g) for X = OH and Rh B (156 mg/g) for X = NH₂. The adsorbents are also easily regenerated for three consecutive cycles without losing their efficiency. We finally demonstrate that MTV-MOFs can be designed to tune the dye removal selectivity and enhance the removal capacity of both MB and RhB in a binary aqueous solution of these dyes.

在本文中，我们利用反应扩散框架（RDF）成功地合成了MOF-199单晶，以合成具有增强性能的多变量金属有机框架（MTV-MOF）。通过整合需要不同官能团的有机连接基，在MOF-199晶体结构中产生缺陷，从而合成MTV-MOF。因此，5-氨基间苯二甲酸（NH ₂-BDC）和5-羟基间苯二甲酸（OH-BDC）与X-BDC：BTC（1：3，1：1）和3的三种不同起始比例分别与1,3,5-苯三甲酸（BTC）混合：1）。研究了该接头对合成的MTV-MOF的形态，其热稳定性和表面积的影响。通过¹阐明了接头在框架中的掺入程度。1 H-NMR光谱表明，结合量随沿管式反应器的位置（RDF的特征）的变化而变化。通过测量其对水溶液中亚甲基蓝（MB）和若丹明B（Rh B）的吸附能力，并与合成的MOF-199进行比较，进一步证明了合成MTV-MOF的增强性能。动力学和热力学研究表明，X-BDC：BTC（1：1）的MTV-MOF对X = OH和Rh B（156 mg / g）表现出最佳的MB（263 mg / g）吸收。 X = NH ₂。吸附剂也很容易连续三个循环再生，而不会损失其效率。我们最终证明，可以设计MTV-MOF来调节染料的去除选择性，并增强MB和RhB在这些染料的二元水溶液中的去除能力。