Prasetya Nicholaus, Wöll Christof
Institute of Functional Interface (IFG), Karlsruhe Institute of Technology Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopolshafen Germany
RSC Adv. 2023 Jul 31;13(33):22998-23009. doi: 10.1039/d3ra03527a. eCollection 2023 Jul 26.
As the world population continues to grow, there is also a rising concern regarding water pollution since this condition could negatively impact the supply of clean water. One of the most recent concerns is related to the pollution that comes from various pharmaceuticals, in particular non-steroidal anti-inflammatory drugs (NSAIDs) since they have been industrially produced at large scale and can be easily purchased as an over-the-counter medicine. Diclofenac is one of the most popular NSAIDs because of its high-effectiveness, which leads to its excessive consumption. Consequently, its presence in water bodies is also continuously increasing. An adsorption process could then be employed as a highly effective method to address this issue. In comparison to other conventional adsorbents such as activated carbon, the use of metal-organic frameworks (MOFs) as an alternative adsorbent is very attractive since it can offer various advantages such as tailorability and high adsorption capacity. In this study, the performance of three water-stable, free-base porphyrin MOFs assembled using zirconia-based nodes, namely MOF-525, MOF-545, and NU-902, for diclofenac adsorption was thoroughly investigated. Interestingly, although all three free-base porphyrin MOFs are assembled using the same building block and have a similar specific surface area (based on the experimental argon physisorption and calculation based on non-localized density functional theory), their diclofenac adsorption capacity is substantially different from one another. It is found that the highest diclofenac adsorption capacity is shown by MOF-525, which has maximum capacity around 792 mg g. This is then followed by MOF-545 and NU-902 that have adsorption capacities around 591 and 486 mg g, respectively. Some possible adsorption mechanisms are then thoroughly discussed that might contribute to this phenomenon. Lastly, their performance is also compared with other MOFs that are also studied for this purpose to show their performance superiority not only in terms of adsorption capacity but also their affinity towards the diclofenac molecule, which might be useful as an adsorption performance indicator in the real condition where the contaminant concentration is considerably low.
随着世界人口持续增长，水污染问题也日益受到关注，因为这种情况可能会对清洁水的供应产生负面影响。最近的一个担忧与各种药物造成的污染有关，特别是非甾体抗炎药（NSAIDs），因为它们已大规模工业化生产，并且作为非处方药很容易买到。双氯芬酸是最受欢迎的非甾体抗炎药之一，因其高效性导致过度消费。因此，其在水体中的存在也在不断增加。吸附过程可以作为解决这个问题的一种高效方法。与其他传统吸附剂如活性炭相比，使用金属有机框架（MOFs）作为替代吸附剂非常有吸引力，因为它可以提供各种优势，如可定制性和高吸附容量。在本研究中，对三种使用基于氧化锆的节点组装的水稳定游离碱卟啉MOFs，即MOF - 525、MOF - 545和NU - 902，用于双氯芬酸吸附的性能进行了深入研究。有趣的是，尽管这三种游离碱卟啉MOFs都是使用相同的构建块组装而成，并且具有相似的比表面积（基于实验氩气物理吸附和基于非局部密度泛函理论的计算），但它们对双氯芬酸的吸附容量却有很大差异。结果发现，MOF - 525表现出最高的双氯芬酸吸附容量，其最大容量约为792 mg/g。其次是MOF - 545和NU - 902，它们的吸附容量分别约为591和486 mg/g。然后详细讨论了一些可能导致这种现象的吸附机制。最后，还将它们的性能与为此目的研究的其他MOFs进行了比较，以表明它们不仅在吸附容量方面，而且在对双氯芬酸分子的亲和力方面的性能优势，这在污染物浓度相当低的实际情况下可能作为吸附性能指标有用。
