Site‐Selective Synthesis and Concurrent Immobilization of Imine‐Based Covalent Organic Frameworks on Electrodes Using an Electrogenerated Acid

Abstract

Imine‐based covalent organic frameworks (COFs) are crystalline porous materials with prospective uses in various devices. However, general bulk synthetic methods usually produce COFs as powders that are insoluble in most of the common organic solvents, arising challenges for the subsequent molding and fixing of these materials on substrates. Here, we report a novel synthetic methodology that utilizes an electrogenerated acid (EGA), which is produced at an electrode surface by electrochemical oxidation of a suitable precursor, acting as an effective Brønsted acid catalyst for imine bond formation from the corresponding amine and aldehyde monomers. Simultaneously, it provides the corresponding COF film deposited on the electrode surface. The COF structures obtained with this method exhibited high crystallinities and porosities, and the film thickness could be controlled. Furthermore, such process was applied for the synthesis of various imine‐based COFs, including a three‐dimensional (3D) COF structure.

A Review on Covalent Organic Frameworks as Artificial Interface Layers for Li and Zn Metal Anodes in Rechargeable Batteries

“…proposed a synthesis method called electrogenic acid (EGA) (Figure 4b). [ 90 ] This method uses EGA that is produced on the electrode surface through electrochemical oxidation of appropriate precursors as an efficacious Brønsted acid activator, which enables the corresponding aldehyde and amine monomers to form imine bonds while deposing corresponding COF films on the electrode surface. For example, they synthesized imido COF film bottom‐up on the electrode using EGA as an activator for the condensation reaction of aldehyde monomers and amine.…”