Electrostatic attraction induces cationic covalent-organic framework to pack inorganic acid ions for promoting proton conduction

A cationic COF (CCOF) was imported to afford stable proton conductive material while the positively charged CCOF can constrain the inorganic anion groups into the framework through an ion exchange process. The inorganic anions could play the role of proton donors to provide a rich source of protons, as well as the proton acceptors for proton transmission, thus forming an interlinked proton conduction pathway within the framework. The proton conductivities of COF materials loaded with different anions have been improved to varying degrees, and the conductivity of H2PO4-@CCOF is up to 3.86 × 10-2 S cm-1 at 100 °C.