fig3

From: The precise synthesis of etched metal-organic frameworks and their applications in electrochemistry

Figure 3. The schematic illustration for the synthetic procedure of (A) hollow Co@NCNs; This figure is adapted from Ref.^[71]. Copyright@2021, Wiley-VCH; (B) single-, double-, and triple-shelled hollow MIL-101; This figure is adapted from Ref.^[73]. Copyright@2017, Wiley-VCH; (C) tZIF-67 hollow nano-frame and the corresponding TEM images; This figure is adapted from Ref.^[75]. Copyright@2021, Wiley-VCH; (D) Schematic illustration of preparing Ni-Fe LDH nanocages with tunable shells. This figure is adapted from Ref.^[87]. Copyright@2021, Wiley-VCH. ZIF: Zeolitic imidazolate framework; TA: tannic acid; SSHM: Single-shelled hollow microcage; DSHM: Double-shelled hollow microcage; TSHM: Triple-shelled hollow microcage; DSNC: Double-shelled nanocage; SSNC: Single-shelled nanocage; MIL: Materials of the Institute Lavoisier; NCN: N-doped carbon nanosheets / Nitrogen-doped carbon network; LDH: layered double hydroxide.