Intermolecular Forces-Oriented Growth of MOF-on-MOF Heterostructures

Well-controlled conjugation of distinct metal-organic frameworks (MOFs) with dissimilar components and structures into a multi-component MOF system is important for the design of myriad materials with structural complexity, integrated properties, and desired applications. Herein, we developed an interesting integration strategy that relies on intermolecular force, and which can overcome the difference in lattice parameters. The strategy uses the pre-formed MOF matrixes as seeds to direct the self-assembly of secondary MOF particles for the construction of hybrid MOFs. As a proof of concept, the representative core-satellite-type Ni-MOF@ZIF-8 and core-shell-type MOF-74@ZIF-8 heterostructures were achieved. Theory calculations elucidate the uncommon formation of well-defined hybrid MOFs by self-assembly of secondary ZIF-8 particles to anchor on Ni-MOF or MOF-74 seed surface via hydrogen bonds and van der Waals interactions. We anticipate that this work opens an avenue to design the multi-component MOF systems from different MOFs with lattice mismatching.