Research Progress in Covalent Organic Frameworks for Energy Storage and Conversion

Covalent organic frameworks (COFs) are a class of porous crystalline materials consisting of organic units connected through covalent bonds.Due to their low density, high surface area and high thermal stability, COFs have found interesting applications in many fields, including molecular adsorption and separation, sensing, catalysis and optoelectronics devices.In particular, two-dimensional (2D) COFs have attracted increasing attention in energy fields.In this perspective, the applications of 2D COFs in energy storage (lithium ion batteries, lithium-sulfur batteries, supercapacitor and fuel cells) and energy conversion (water splitting and reduction of carbon dioxide) are reviewed.In addition, we will also discuss the remaining challenging issues.