Synthesis of Bi-Metallic Organic Frameworks and Their Capacitive Behaviors According to Metal Mixing Ratio

Metallic organic frameworks (MOFs) with mixed metals has attracted attention as electrochemical energy storage material because it has high specific surface area, synergy of two metals, and a new crystal structure different from that of conventional MOF. In this study, we synthesized MOFs, including nickel and zinc, by hydrothermal method at a time. We investigated the effect of two metal ratios on the capacitive behavior. Through the structure and morphology analysis, it was found that Ni–Zn-MOF forms a completely different crystal structure from MOF using one metal, and found that it is a porous material. As a result of electrochemical measurements with cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD), the specific capacitance of Ni–Zn-MOF 2:1 with a nickel to zinc ratio of 2:1 was 616 F g⁻¹ at a current density was 1 A g⁻¹.