Comparative electrochemical evaluation of trimetallic Zn-Cu-Mo and Mg-Cu-Mo metal organic frameworks-derived nanocomposites for supercapacitor applications

Abstract

Metal-organic frameworks (MOFs) have attracted considerable attention for electrochemical energy storage due to their redox-active metal centers, high surface area and tunable porosity. Herein, we synthesized and examined two-dimensional (2D) trimetallic nanocomposites of Zn-Cu-Mo and Mg-Cu-Mo MOFs, which were prepared via a straightforward hydrothermal method and evaluated as electrode materials for supercapacitor applications. The incorporation of multiple metal centers within the framework is expected to influence the electronic and electrochemical behaviour of the materials. Both MOFs exhibit porous, cube-shaped morphology and provide accessible electroactive sites and facilitate electrolyte diffusion. Electrochemical performance of the synthesized MOFs was evaluated in 1 M KOH aqueous electrolyte. The Zn-Cu-Mo-MOF shows a maximum specific capacitance of ~285.5 Fg -1 higher than that of Mg-Cu-Mo-MOF, that exhinbit ~191.5 Fg -1 under comparable conditions. The corresponding power densities reached 1020 Wkg -1 for Zn-Cu-Mo and 832 Wkg -1 for Mg-Cu-Mo. The higher electrochemical performance of the Zn-based MOF composite can be attributed to its smaller particle size, rougher surface texture and more open porous architecture, which facilitates faster ion diffusion and greater exposure of electroactive sites. Cyclic voltammetry and galvanostatic charge-discharge analysis indicate reversible faradaic behavior and stable charge storage characteristics. Our results show that the prepared trimetallic MOFs exhibit promising electrochemical properties and may serve as potential electrode materials for supercapacitors and related energy storage systems.