Effect of steric hindrance on the interfacial connection of MOF-on-MOF architectures

Abstract

MOF-on-MOF is attracting great attention due to its improved and/or synergistic properties not exhibited in a single MOF. In particular, the non-isostructural pairs of MOF-on-MOFs can have great potentials induced...

Advancing Metal–Organic Framework Designs for Room-Temperature Chemiresistive Gas Sensors

“…Finally, the stability of proposed MOF-on-MOF pairs is evaluated through DFT calculation that provides the net energy stabilization, which considers both the energy penalty from linker strain and the energy stabilization from the bond formation. Subsequent studies have shown that the energy barrier at the interface plays a crucial role in the stability of the final material . The applicability of this algorithm’s predictions was confirmed with successful synthesis of six MOF-on-MOF pairs using standard solvothermal MOF synthesis methods.…”

“…Subsequent studies have shown that the energy barrier at the interface plays a crucial role in the stability of the final material. 122 The applicability of this algorithm's predictions was confirmed with successful synthesis of six MOF-on-MOF pairs using standard solvothermal MOF synthesis methods. Conversely, the mismatched pairs result in separately grown crystals or polycrystalline core−shell structures with an excess of the shell MOF.…”

“…119−121 Therefore, the selection of MOF pairs is critical for the practical manufacture of MOFon-MOFs, especially core−shell type (MOF@MOF) materials with the desired functionality. 122 Unfortunately, the diversity of MOFs results in numerous combinations of pair candidates, forcing researchers to expend a myriad of efforts in searching for compatible pairs.…”

“…The MOF-on-MOF materials can be categorized into lattice-matched and mismatched systems depending on whether the MOF pairs constituting the architecture have similar lattice parameters (Figure a) . The synthetic methods for MOF-on-MOF should consider the degree of lattice similarity between the two-component MOFs, as the energy barrier to heterogrowth is lower in lattice-matched pairs. , In lattice-matched systems, MOF-on-MOF materials are generally synthesized by the conventional solvothermal method where core MOF is added as a seed to create interfaces that contribute to the integration of the two MOFs. − However, overcoming the high energy barrier posed by the lattice-mismatched growth of shell-MOF on core-MOF requires synthetic controls, possibly involving nucleation or growth kinetic adjustments through surface functionalization and temperature modification. − Therefore, the selection of MOF pairs is critical for the practical manufacture of MOF-on-MOFs, especially core–shell type (MOF@MOF) materials with the desired functionality . Unfortunately, the diversity of MOFs results in numerous combinations of pair candidates, forcing researchers to expend a myriad of efforts in searching for compatible pairs.…”

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

“…[60][61][62][63] Typically, the assembly of MOF-on-MOF configurations is involved in the arrangement of two or more MOF species through lattice matching. [64][65] Researchers commonly select easy-to-prepare and stable MOFs as templates for the secondary growth of MOFs by externally introducing metal ions and organic linkers. [66][67]102] In cases of high lattice compatibility, secondary MOFs can effectively nucleate and grow atop primary MOF substrates.…”