Ligand-induced growth of Co/Cu bimetallic metal organic frameworks with different morphology for energy storage

The morphological structure is of particular importance to the energy storage properties of metal organic framework (MOF) electrode materials. Herein, a series of Co/Cu bimetallic MOFs were achieved by the facile hydrothermal method of cobalt nitrate and copper nitrate with phthalic acid (PA), terephthalic acid (TPA) and isophthalic acid (IPA). Co/Cu–IPA MOF, prepared by the reaction between cobalt nitrate, copper nitrate and IPA ligand, exhibits a loose lamellar structure while Co/Cu–PA MOF and Co/Cu–TPA MOF display a thin-strip structure. Co/Cu–IPA MOF displays a high specific area of 375.8 m 2 g −1 compared with Co/Cu–PA MOF (44.09 m 2 g −1 ) and Co/Cu–TPA MOF (9.64 m 2 g −1 ). Besides, Co/Cu–IPA MOF possesses more Cu + content. Therefore, Co/Cu–IPA MOF shows a high specific capacitance of 369.1 F g −1 at 1 A g −1 . A Co/Cu–IPA MOF//AC asymmetric device was constructed successfully. This device shows an energy density of 6.81 W h kg −1 at a power density of 500 W kg −1 .