Porous covalent–organic materials: synthesis, clean energy application and design

Porous covalent–organic materials (COMs) are a fascinating class of nanoporous material with high surface area and diverse pore dimensions, topologies and chemical functionalities. These materials have attracted ever-increasing attention from different field scientists, owing to their potential applications in gas storage, adsorptive separation and photovoltaic devices. The versatile networks are constructed from covalent bonds (B–O, C–C, C–H, C–N, etc.) between the organic linkers by homo- or hetero-polymerizations. To design and synthesize novel porous COMs, we first summarize their synthesis methods, mainly including five kinds of coupling reaction, i.e. boronic acid, amino, alkynyl, bromine and cyan group-based coupling reactions. Then, we review the progress of porous COMs in clean energy applications in the past decade, including hydrogen and methane storage, carbon dioxide capture, and photovoltaic applications. Finally, to improve their gas adsorptive properties, four possible strategies are proposed, and high-capacity COMs for gas storage are designed by a multiscale simulation approach.