Synthesis of Covalent Organic Framework Films at Interfaces#

The diverse topological structure, designable building blocks, ordered pores and crystalline architecture of covalent organic frameworks (COFs) make them attractive in many application fields. However, COF materials obtained by solvothermal synthesis are generally poorly soluble powders and difficult to post-process, which may impede some applications of COFs. The direct preparation of COF films is effective to overcome the limitations of poor solubility of COFs. This article reviews the synthesis of COF films at interfaces and the applications of COF films. At first, the synthesis strategies for preparing monolayer COF with large crystalline domains on solid substrates are introduced. Then we discuss interface synthesis methods, including solid-liquid, liquid-liquid and liquid-gas interface, for various COF films. Subsequently, the applications of COF film in many fields such as photoelectric conversion, fluorescence, electronic devices, chemical sensing, electrocatalysis, and molecular separation are introduced briefly. Finally, prospects for the interface synthesis and application expansion of COF films are discussed.