How the planarity of two dimensional covalent organic frameworks affect gas adsorption and diffusion: A data mining, simulation, and experiment united study

Abstract The planarity of two‐dimensional covalent organic frameworks (2D‐COFs) was demonstrated to show a significant and complex impact on their gas adsorption performance. However, the intrinsic mechanism underlying the intricate phenomenon remains unclear. Herein, a machine learning‐assisted data mining, simulation, and experiment combined study was performed to elucidate the complex impact of planar features of 2D‐COFs on gas adsorption and diffusion properties. A workflow was established for automatically assessing the planarity of 2D‐COFs. Compared with the flat configuration, the twisted and wavy configurations enhance the van der Waals interactions, promoting the adsorption of most nonpolar gases. Meanwhile, both the twisted and wavy configurations demonstrated an improved effect on gas diffusion. Gas adsorption and kinetic measurements on 2D‐COFs with similar physical and chemical properties but different planar features verified the theoretical finding. This work provides original insights and opens a new research paradigm for the study on the planarity of 2D‐COFs.