Specific Oriented Metal鈥揙rganic Framework Membranes and Their Facet-Tuned Separation Performance

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• 作者：Yiyin Mao ; Binbin Su ; Wei Cao ; Junwei Li ; Yulong Ying ; Wen Ying ; Yajun Hou ; Luwei Sun ; Xinsheng Peng
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2014
• 出版时间：September 24, 2014
• 年：2014
• 卷：6
• 期：18
• 页码：15676-15685
• 全文大小：651K
• ISSN：1944-8252

文摘

Modulating the crystal morphology, or the exposed crystal facets, of metal鈥搊rganic frameworks (MOFs) expands their potential applications in catalysis, adsorption, and separation. In this article, by immobilizing the citrate modulators on Au nanoparticles and subsequently being fixed on solid copper hydroxide nanostrands, a well-intergrown and oriented HKUST-1 cube crystal membrane was formed at room temperature. In contrast, in the absence of Au nanoparticles, well-intergrown and oriented cuboctahedron and octahedron membranes were formed in water/ethanol and ethanol, respectively. The gas separation performances of these HKUST-1 membranes were tuned via their exposed facets with defined pore sizes. The HKUST-1 cube membrane with exposed {001} facets demonstrated the highest permeance but lowest gas binary separation factors, while the octahedron membrane with exposed {111} facets presented the highest separation factors but lowest permeance, since the window size of {111} facets is 0.46 nm which is smaller than 0.9 nm of {001} facets. Separation of 0.38 nm CO₂ from 0.55 nm SF₆ was realized by the HKUST-1 octahedron membrane. As a proof of concept, this will open a new way to design MOF-related separation membranes by facet controlling.

Keywords:

facets-tuned; metal鈭抩rganic frameworks; thin films; separation membranes; Au nanoparticles