Site-specific anisotropic assembly of amorphous mesoporous subunits on crystalline metal–organic framework

Abstract

As an important branch of anisotropic nanohybrids (ANHs) with multiple surfaces and functions, the porous ANHs (p-ANHs) have attracted extensive attentions because of the unique characteristics of high surface area, tunable pore structures and controllable framework compositions, etc. However, due to the large surface-chemistry and lattice mismatches between the crystalline and amorphous porous nanomaterials, the site-specific anisotropic assembly of amorphous subunits on crystalline host is challenging. Here, we report a selective occupation strategy to achieve site-specific anisotropic growth of amorphous mesoporous subunits on crystalline metal–organic framework (MOF). The amorphous polydopamine (mPDA) building blocks can be controllably grown on the {100} (type 1) or {110} (type 2) facets of crystalline ZIF-8 to form the binary super-structured p-ANHs. Based on the secondary epitaxial growth of tertiary MOF building blocks on type 1 and 2 nanostructures, the ternary p-ANHs with controllable compositions and architectures are also rationally synthesized (type 3 and 4). These intricate and unprecedented superstructures provide a good platform for the construction of nanocomposites with multiple functionalities and understanding of the structure-property-function relationships.

Interfacial Engineering of Heterogeneous Reactions for MOF‐on‐MOF Heterostructures

“…Lattice mismatch [131] Cu 2 (BPDC) ZIF-8@PDA@ZIF-67 ZIF-8@PDA ZIF-67 PDA-template growth [153] COF-303@MOF-5 MOF-5 COF-303 COF-on-MOF composite [154] NiFe-MS/MOF@NF NF NiFe-MS/MOF NF-template growth [155] (Trigonal, a = 36.25 Å, c = 6.84 Å) in Figure 4e. [121] At the interface of the MOF precursors, the spherulite surfaces underwent dissolution and recrystallization resulting in the generation of defects that served as nucleation sites for the secondary growth of MOFs.…”

“…Previously, Li and his colleagues showcased the selective epitaxial growth of amorphous polydopamine (mPDA) on (100, type 1) or (110, type 2) crystal facets of crystalline ZIF‐8 to obtain porous anisotropic nanohybrids (p‐ANHs) in Figure a,b. [ 153 ] Due to the distinct coordination environment of Zn(II) cations on both facets of the truncated rhombic dodecahedra of ZIF‐8, the assembled mPDA nanosheets exhibited anisotropic growth along the faces or edges to form binary superstructures. Subsequently, using these templates, resulted in the growth of ternary MOF materials with different configurations (types 3 and 4) based on the exposed facets of the template by secondary epitaxial growth.…”

Recent Advances in Multifunctional Reticular Framework Nanoparticles: A Paradigm Shift in Materials Science Road to a Structured Future

“…a-c Characterization of MOF p-ANHs nanoparticle using a SEM, b HAADF-STEM with EDX Elemental Mapping, and c TEM imaging in zone axis analysis along [001], [011], and [ 110 ] with their corresponding models and SAED patterns (reproduced with permission from Ref. [ 187 ]. Copyright 2023, Springer Nature).…”

Hierarchical Porous N-Doped Carbon Particles Derived from ZIF-8 as Highly Efficient H2S Selective Oxidation Catalysts

“…Carbon-based materials have found widespread applications in the selective oxidation of H 2 S owing to their large specific surface areas, diverse sources, modifiable surface chemistry, and exceptional antipoisoning properties. ,, N-doped carbon materials, in particular, have garnered extensive attention due to the abundant basic sites on the surface, which are beneficial to facilitate the adsorption and dissociation of H 2 S and O 2 . ,, Metal–organic frameworks (MOFs) have emerged as promising precursors to porous carbon due to their tunable size, significant specific surface area, high porosity, and facile functionalization. − Among these, ZIF-8 stands out as a representative class of MOF materials, and N-doped carbon catalysts derived from ZIF-8 through carbonization under inert atmospheres have been widely used in various fields such as energy storage, catalysis, and gas adsorption and separation. − Despite these advantages, N-doped carbon catalysts derived from ZIF-8 inherit common drawbacks associated with MOF-derived carbon materials, notably the intrinsic nature of microporosity. − This microporous nature significantly limits gas mass-transfer efficiency and is not conducive to the selective oxidation of H 2 S. In our previous work, ZIF-8-derived N-doped carbon catalysts with varying particle sizes were prepared for H 2 S oxidation . It was observed that when the particle size of the catalysis increased from 0.12 to 1.06 μm the ratio of micropore volume to total volume ( V micro / V total ) increased from 48.0% to 79.2%, while H 2 S conversion decreased from 100% to 70.8%.…”