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![Recent progress in strategies for preparation of metal-organic frameworks and their hybrids with different dimensions](https://image.oaes.cc/722f76d1-0f45-4512-ac2f-6b758619b7bd/5312.fig.4.jpg)
Figure 4. (A) Schematic diagram of the electrostatic spinning unit. (B) The synthesis of hollow particle-based N-doped carbon nanofibers (HPCNFs-N). (C and D) FESEM and TEM images of the PAN/ZIF-8 composite nanofibers. (E and F) FESEM and TEM images of the HPCNFs-N sample. (G) Diagrammatic representation of the different synthetic routes for the structuring of HKUST-1 into MOF NFs. (A) Adapted with permission[101]. Copyright 2007, American Chemical Society. (B-F) Adapted with permission[113]. Copyright 2017, The Royal Society of Chemistry. (G) Adapted with permission[115]. Copyright 2021, Springer Nature. MOFs: Metal-organic frameworks; FESEM: field emission scanning electron microscopy; PAN: polyacrylonitrile; NFs: nanofibers.