Fig. 3.

a COFs with different pore structures and chemical interaction with guest molecules I. Interpenetrated microporous framework constructed from undecorated edges. II. Non-interpenetrated mesoporous framework built up from partially decorated edges, in which the pore shrinkage or collapse would happen after the removal of guest molecules. III. Non-interpenetrated mesoporous framework created by highly decorated edges, in which the pores can be maintained entirely after the removal of guest molecules. Adapted with permission [76]. Copyright © 2020 American Chemical Society. b Schematic diagram for the temperature-swing gas exfoliation of NUS-30 from bulk layered powder to ultrathin 2D nanosheets. Adapted with permission [83]. Copyright © 2018 American Chemical Society. c I. Two-fold interpenetrated PTS network; II. space-filling model viewed from the A axis; III. space-filling model viewed from the C axis. Adapted with permission [77]. Copyright © 2016 American Chemical Society