Chakraborty Anindita, Laha Subhajit, Kamali Kesavan, Narayana Chandrabhas, Eswaramoorthy Muthusamy, Maji Tapas Kumar
Chemistry and Physics of Materials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur, Bangalore 560064, India.
Inorg Chem. 2017 Aug 21;56(16):9426-9435. doi: 10.1021/acs.inorgchem.7b01601. Epub 2017 Aug 9.
Self-assembly of metal-organic framework (MOF) nanoparticles (NPs) with a functional material can result in MOF nanocomposites having new and advanced properties along with the fabrication of new nanoscopic structures. However, such assembly of MOFs has not been realized to date. Here we report self-assembled nanocomposites of the zeolitic imidazolate framework (ZIF-8) and layered aminoclay (AC) for the first time, and the ZIF-8@AC composites exhibit significantly enhanced adsorption properties in comparison to those of pristine ZIF-8 nanoparticles. Four different composites denoted as ZIF-8@AC-1, ZIF-8@AC-2, ZIF-8@AC-3, and ZIF-8@AC-4 were synthesized by varying the clay content, and their AC contents were found to be 12.1, 18.3, 22.2, and 27.2 wt %, respectively. The composites were thoroughly characterized by PXRD, FTIR, Raman, and various microscopic techniques (FESEM, TEM, and STEM). The formation of the composites is driven by the specific interaction between unsaturated Zn(II) sites of ZIF-8 nanoparticles and NH groups of the aminoclay, which was validated from ζ potential and Raman spectroscopic measurements. The adsorption studies of the desolvated composites were also carried out in detail. The best performance is achieved with one of the composites, which exhibits a 42% increase in BET surface area while CO uptake at 298 K is doubled in comparison to the ZIF-8 nanoparticles.
金属有机框架（MOF）纳米颗粒（NPs）与功能材料的自组装可形成具有新颖和先进特性的MOF纳米复合材料，同时还能制造出新的纳米结构。然而，迄今为止尚未实现MOF的这种组装。在此，我们首次报道了沸石咪唑酯框架（ZIF-8）与层状氨基粘土（AC）的自组装纳米复合材料，与原始ZIF-8纳米颗粒相比，ZIF-8@AC复合材料的吸附性能显著增强。通过改变粘土含量合成了四种不同的复合材料，分别表示为ZIF-8@AC-1、ZIF-8@AC-2、ZIF-8@AC-3和ZIF-8@AC-4，发现它们的AC含量分别为12.1、18.3、22.2和27.2 wt%。通过粉末X射线衍射（PXRD）、傅里叶变换红外光谱（FTIR）、拉曼光谱以及各种显微镜技术（场发射扫描电子显微镜（FESEM）、透射电子显微镜（TEM）和扫描透射电子显微镜（STEM））对复合材料进行了全面表征。复合材料的形成是由ZIF-8纳米颗粒的不饱和Zn（II）位点与氨基粘土的NH基团之间的特定相互作用驱动的，这已通过ζ电位和拉曼光谱测量得到验证。还详细开展了去溶剂化复合材料的吸附研究。其中一种复合材料表现出最佳性能，其比表面积增加了42%，而在298 K下的CO吸附量相比ZIF-8纳米颗粒增加了一倍。
