Department of Chemistry, The City College and the Graduate School of the City University of New York, 160 Convent Avenue, New York, New York 10031, USA.
Langmuir. 2010 Oct 5;26(19):15302-9. doi: 10.1021/la1021092.
New composites based on HKUST-1 and graphene layers are tested for ammonia adsorption at room temperature in both dry and moist conditions. The materials are characterized by X-ray diffraction, FT-IR spectroscopy, adsorption of nitrogen, and thermal analyses. Unlike other MOF/GO composites reported in previous studies, these materials are water-stable. Ammonia adsorption capacities on the composites are higher than the ones calculated for the physical mixture of components, suggesting the presence of a synergetic effect between the MOF and graphene layers. The increased porosity and dispersive forces being the consequence of the presence of graphene layers are responsible for the enhanced adsorption. In addition to its retention via physical forces, ammonia is also adsorbed via binding to the copper sites in HKUST-1 and then, progressively, via reaction with the MOF component. This reactive adsorption is visible through two successive changes of the adsorbents' color during the breakthrough tests. More ammonia is adsorbed in moist conditions than in dry conditions owing to its dissolution in a water film present in the pore system.
基于 HKUST-1 和石墨烯层的新型复合材料在室温下进行了干燥和潮湿条件下氨吸附的测试。通过 X 射线衍射、傅里叶变换红外光谱、氮气吸附和热分析对材料进行了表征。与之前研究中报道的其他 MOF/GO 复合材料不同，这些材料具有耐水性。复合材料上的氨吸附容量高于组分物理混合物计算的吸附容量，表明 MOF 和石墨烯层之间存在协同效应。由于石墨烯层的存在，增加了孔隙率和分散力，从而提高了吸附性能。除了通过物理力保留氨之外，氨还通过与 HKUST-1 中的铜位结合，然后与 MOF 组分反应而被吸附。在穿透测试过程中，吸附剂颜色的两次连续变化可见这种反应性吸附。由于氨溶解在孔系统中存在的水膜中，因此在潮湿条件下比在干燥条件下吸附更多的氨。
