Advances in solvent-free syntheses of covalent organic frameworks towards catalysis and battery applications

Abstract

The solvent-free syntheses of covalent organic frameworks (COFs) can eliminate the need for toxic and volatile solvents, facilitate processing and enable large-scale production to lower the cost, acting as an emerging and green synthetic method towards important applications like catalysis or batteries. In this review, we will focus on the solvent-free syntheses of COFs, aiming to summarize synthesis methods, available COF structures and properties, and their related applications in catalysis (e.g., photocatalytic hydrogen evolution or H₂O₂ synthesis, electrocatalytic CO₂ reduction, water splitting, etc.) and batteries (e.g., hydrogen fuel cells, lithium/potassium-ion batteries, Zn–air batteries, supercapacitors, etc.). We will also briefly outline the current challenges and prospects faced in the solvent-free syntheses of COFs, aiming to guide the recent advancements and future directions for the development of solvent-free synthesized COFs and their related applications.