Dipartimento di Scienze Chimiche e Geologiche, Università di Cagliari, Cittadella Universitaria, S.S. 554 bivio Sestu, 09042 Monserrato (CA), Italy.
Laboratorio NEST Scuola Normale Superiore di Pisa, 56127 Pisa, Italy.
Int J Mol Sci. 2021 Jan 14;22(2):788. doi: 10.3390/ijms22020788.
Synthetic organic dyes are widely used in various industrial sectors but are also among the most harmful water pollutants. In the last decade, significant efforts have been made to develop improved materials for the removal of dyes from water, in particular, on nanostructured adsorbent materials. Metal organic frameworks (MOFs) are an attractive class of hybrid nanostructured materials with an extremely wide range of applications including adsorption. In the present work, an iron-based Fe-BTC MOF, prepared according to a rapid, aqueous-based procedure, was used as an adsorbent for the removal of alizarin red S (ARS) and malachite green (MG) dyes from water. The synthesized material was characterized in detail, while the adsorption of the dyes was monitored by UV-Vis spectroscopy. An optimal adsorption pH of 4, likely due to the establishment of favorable interactions between dyes and Fe-BTC, was found. At this pH and at a temperature of 298 K, adsorption equilibrium was reached in less than 30 min following a pseudo-second order kinetics, with k″ of 4.29 × 10 and 3.98 × 10 g∙mg min for ARS and MG, respectively. The adsorption isotherm followed the Langmuir model with maximal adsorption capacities of 80 mg∙g (ARS) and 177 mg∙g (MG), and K of 9.30·10 L∙mg (ARS) and 51.56·10 L∙mg (MG).
合成有机染料广泛应用于各个工业领域，但也是最有害的水污染物之一。在过去的十年中，人们做出了巨大的努力来开发用于从水中去除染料的改良材料，特别是在纳米结构吸附材料方面。金属有机骨架（MOFs）是一类具有广泛应用的混合纳米结构材料，包括吸附。在本工作中，一种基于铁的 Fe-BTC MOF 通过快速的水基方法制备，用作从水中去除茜素红 S（ARS）和孔雀石绿（MG）染料的吸附剂。详细表征了合成材料，同时通过紫外-可见光谱监测染料的吸附。发现吸附的最佳 pH 值为 4，这可能是由于染料与 Fe-BTC 之间建立了有利的相互作用。在该 pH 值和 298 K 温度下，吸附平衡在不到 30 分钟内达到，遵循拟二级动力学，ARS 和 MG 的 k″值分别为 4.29×10 和 3.98×10 g·mg min。吸附等温线遵循 Langmuir 模型，最大吸附容量分别为 80 mg·g（ARS）和 177 mg·g（MG），K 值分别为 9.30·10 L·mg（ARS）和 51.56·10 L·mg（MG）。
