Nanoengineering Multilength Scale Porous Hierarchy in Mesoporous Metal-Organic Framework Single Crystals

Developing a reliable method for constructing mesoporous metal–organic framework (MOF) with single-crystalline form remains a challenging task despite numerous efforts. This study presents a solvent-mediated assembly method for fabricating zeolitic imidazolate framework (ZIFs) single-crystal nanoparticles with well-defined micro-mesoporous structure using polystyrene-block-polyethylene oxide diblock copolymer micelles as a soft-template. The precise control of particle sizes, ranging from 85 nm to 1.2 μm, is achieved through the regulation of nucleation and crystal growth rates, while maintaining consistent pore diameters in mesoporous nanoparticles and a rhombohedral dodecahedron morphology. Furthermore, this study presents a robust platform for nanoarchitecturing to prepare hierarchically porous materials (e.g., core-shell and hollow structures) using the micro-mesoporous ZIF series, including microporous ZIF@mesoporous ZIF, hollow mesoporous ZIF, and mesoporous ZIF@mesoporous ZIF. Such a multimodal pore design, ranging from microporous to micro/mesoporous and further micro/meso/macroporous, provides significant evidence for the future possibility of MOF structural design, which has not yet been presented.