fig4

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.