A new method to position and functionalize metal-organic framework crystals

Abstract

With controlled nanometre-sized pores and surface areas of thousands of square metres per gram, metal-organic frameworks (MOFs) may have an integral role in future catalysis, filtration and sensing applications. In general, for MOF-based device fabrication, well-organized or patterned MOF growth is required, and thus conventional synthetic routes are not suitable. Moreover, to expand their applicability, the introduction of additional functionality into MOFs is desirable. Here, we explore the use of nanostructured poly-hydrate zinc phosphate (α-hopeite) microparticles as nucleation seeds for MOFs that simultaneously address all these issues. Affording spatial control of nucleation and significantly accelerating MOF growth, these α-hopeite microparticles are found to act as nucleation agents both in solution and on solid surfaces. In addition, the introduction of functional nanoparticles (metallic, semiconducting, polymeric) into these nucleating seeds translates directly to the fabrication of functional MOFs suitable for molecular size-selective applications.

General incorporation of diverse components inside metal-organic framework thin films at room temperature

“…Most previously reported functional component-encapsulated MOF composites incorporate a single functional component 27,34,[38][39][40][41][42][43][44][45] , which limits their functionality and applications. However, by our method, two functional components, ferritin and 20-nm Au NPs, are successfully co-incorporated into HKUST-1 thin films through a one-pot process ( sandwich thin film was formed by alternately filtering CHNs and PS spheres on anodic alumina oxide (AAO) substrates ( Supplementary Fig.…”

“…Afterward, to confine the growth of MOFs on the surfaces of nanoparticles, metal oxide nanostructures can be employed as a metal source that is directly converted to an MOF-surrounded composite 43,44 . Similarly, Falcaro et al have applied functional nanoparticle-encapsulated a-hopeite as a nucleating agent to position and encapsulate the functional components in MOF-5 with core/shell structures 45,46 . However, most of the aforementioned methods require relatively high temperatures and long reaction times 27,34,[38][39][40][41][42][43][44][45][46] , and the obtained NP/MOF composite powders 27,34,[38][39][40][41][42][43][44] are not suitable for thin film devices 10,43,44 .…”

Exceptionally Long-Lived Charge Separated State in Zeolitic Imidazolate Framework: Implication for Photocatalytic Applications

“…This strategy has been widely used in developing zeolite-based photocatalysts 20 and recently in preparing MOF/nanocomposite or MOF/molecular catalyst hybrids, 19,21,22 yet suffers from challenges, notably the difficulty in preventing the guest material aggregation and the lack of the control over spatial distribution and homogeneity. 21,[23][24][25][26] An alternative approach, which has recently been used in developing photoactive MOFs, is to develop the framework which exhibits an intrinsic photochemical response and thereby can be directly applied in photocatalysis. 27,28 As photocatalysis is based on a charge-transfer (CT) event following photoexcitation, it is essential to gain an intimate knowledge of the excited-state and charge transport properties within the ZIF framework, the properties that remain unexplored.…”

A copper-phyllosilicate core-sheath nanoreactor for carbon–oxygen hydrogenolysis reactions

“…However, these approaches are not generally applicable because they restrict chemical composition and functionality. Recently, the encapsulation of individual NPs in morphologically well-defined inorganic shells or tubes has received much attention because of the thermal and chemical stabilities in catalysis [12][13][14][15] .…”