Atypical Hybrid Metal–Organic Frameworks (MOFs): A Combinative Process for MOF‐on‐MOF Growth, Etching, and Structure Transformation

Abstract

The structural, compositional, and morphological features of metal–organic frameworks (MOFs) govern their properties and applications. Construction of hybrid MOFs with complicated structures, components, or morphologies is significant for the development of well‐organized MOFs. An advanced route is reported for construction of atypical hybrid MOFs with unique morphologies and complicated components: 1) MOF‐on‐MOF growth of a 3D zeolitic imidazolate framework (ZIF) on a ZIF‐L template, 2) etching of a part of the 2D ZIF‐L template, and 3) structural transformation of 2D ZIF‐L into 3D ZIF. The formation of core–shell‐type MOF rings and plates is controlled by regulating the three processes. The formation route for the core–shell‐type MOF rings and plates was monitored by tracking changes in morphology, structure, and composition. Carbon materials prepared from the pyrolysis of the core–shell‐type hybrid MOFs displayed enhanced oxygen reduction reaction activities compared to their monomeric counterparts.

Simple, scalable mechanosynthesis of metal–organic frameworks using liquid-assisted resonant acoustic mixing (LA-RAM)

“…Comparison of Xray reections suggests the unexpected product is ZIF-L (see ESI †), a layered 2-D Zn(MeIm) 2 framework containing additional neutral HMeIm ligands (CSD code IWOZOL). 13,14,24 The observation of ZIF-L was particularly intriguing as this phase has not yet been observed in any reports on mechanochemical or solvent-free synthesis of ZIF-8, and has been signicantly less explored compared to ZIF-8. Consequently, we explored the possibility of using RAM for targeted synthesis of ZIF-L.…”

“…1c and d). Importantly, LA-RAM also enabled a simple, rapid route for making the metastable 2-D layered MOF material ZIF-L 13,14 and its Co(II) analogue, neither of which have previously been obtained via mechanochemistry. Using ZIF-L as a model, the scale-up of LA-RAM synthesis of MOFs from hundreds of milligrams to at least 25 grams is demonstrated.…”

Ternary MOF-on-MOF heterostructures with controllable architectural and compositional complexity via multiple selective assembly

“…To improve the complexity of MOF-based composites with broadened functions, the assembly of MOFs and other nanomaterials is a promising approach 20 – 23 . Meanwhile, conjugation of two or more different MOFs into one MOF-on-MOF hybrid material presents another strategy for the fabrication of complicated MOF hybrids with unprecedented nanostructures 24 – 35 .…”

Synthesis of MgNiO2/CoNC-Based Ternary Metallic Dual-Active Interfacial Porous Hollow Nanocages as Efficient Oxygen Reduction Reaction and Oxygen Evolution Reaction Bi-Functional Electrocatalysts

“…However, all of the aforementioned catalysts rarely possess satisfactory ORR and OER activities simultaneously. Additionally, they are also restricted by their excessive cost and deficient stability (Dai et al, 2015;Liang et al, 2016;Zhang et al, 2017;Chen et al, 2019;Lee et al, 2019). Thus, making extensive studies to seek alternative catalysts based on non-precious metals with rich resource, low cost, and comparable electrocatalytic activity for both ORR and OER is urgent (Jahan et al, 2013;Shi and Zhang, 2016;Zhu et al, 2019b;Gao et al 2017).…”