Emerging Covalent Organic Frameworks for Efficient Proton Conductors

Covalent organic frameworks (COFs) are a class of crystalline porous materials with ordered nanochannels, designable functionality, and excellent chemical/thermal stability. Taking advantage of these exceptional properties, COFs have emerged as ideal platforms for designing proton conductors. Since the first successful realization of COFs as proton conductors in 2014, considerable efforts have been devoted to this field. This Review summarizes the evolution of COFs as proton conductors from powder-pressed pellets to self-standing membranes, as well as the properties of these proton-conducting COFs. Finally, current challenges and prospects for COFs in the field of proton conductors are discussed.