Protonated Emeraldine Polyaniline Threaded MIL-101 as a Conductive High Surface Area Nanoporous Electrode

The low electrical conductivity of metal organic frameworks (MOFs) is currently the major hurdle for their electrochemical applications. Herein, we render an MOF with a 9-order magnitude higher electrical conductivity by threading a conductive polymer in the MOF cavities at molecular scale. Such electrically conductive MOF-protonated emeraldine polyaniline (PANI) threaded in MIL-101(Cr), PANI∼MIL-101, demonstrates superb electrical conductivity of 0.01 S cm-1 with the ultrahigh surface area retained (2065 m2 g-1) because of the full penetration of PANI and its uniform distribution within MIL-101 cavities. Effective electron transport is established in the PANI∼MIL-101 structure via π-πstacking among polyaniline chains and n → π∗ and π-πinteractions between polyaniline and MIL-101. We demonstrate PANI∼MIL-101 is an effective electrode in Fe-ion sensors and all-Fe redox flow batteries. One coating of this conductive MOF can serve as alternate for a microelectrode array. This work now opens up a new class of conductive MOFs with high surface area and nanoporosity, which are promising for electrochemical applications. © 2021 American Chemical Society.