A flexible route to crisp-like metal-organic framework derivatives by crystalline transformation

Flexible design is one of the most significant features of metal-organic frameworks (MOFs) in that it can improve the efficiency of MOFs in storage, separation, sensing, and other applications. Herein, we reported a facile strategy to perform the flexible crystalline transformation of MOF polyhedra into their crisp-like derivatives. A mild hydrothermal process involved a crystalline change from ZIF-7 to Zn₂(bim)₄ and a morphological change from an individual polyhedron to a string of nanosheets. Based on the crisp-like morphology which possessed abundant accessible active sites, composites such as Zn₂(bim)₄@ZnS and Zn₂(bim)₄@CoS could be obtained by further sulfidation and applied in oxygen evolution reactions (OERs) with a lower overpotential (330 mV) and good stability compared with a commercial IrO₂ electrode. The well-organized Zn₂(bim)₄ nanosheets with crisp-like morphology demonstrate an interesting crystalline transformation route to construct complicated nanostructures which are hardly achievable by direct synthesis, showing great promise for designing functional derived materials from MOFs.