A Dual-Template MOF/ZIF Approach for Structurally Optimized Metal Oxide@CNT and Porous Carbon Electrodes in Supercapacitors

Abstract

Metal-organic frameworks (MOFs)-derived transition metal oxides (TMOs) combined with carbon nanotubes (CNTs) offer enhanced electronic conductivity and high theoretical capacitance, making them promising nanostructured electrodes for electrochemical energy storage. This work presents an efficient strategy for synthesizing MOF-derived TMO/CNT composite as next-generation supercapacitor electrodes. Leveraging the MOF conversion chemistry, porous Ni/Co MOF (NCM) precursor was utilized as a self-sacrificing template to produce a nickel cobalt oxide composited with CNT (NCM-derived NCO@CNT), which overcomes the intrinsic drawbacks of pristine MOFs, including low electronic conductivity and structural instability, while retaining their high specific capacitance. The strategic integration of components enhances electronic transfer kinetics through the CNT framework and improves ionic transport by maintaining the material’s inherent porosity. Electrochemical analysis shows that NCM-derived NCO@CNT composite delivers an impressive specific capacitance of 1466.6 F g-1 at 1 mA cm-2, confirming the benefits of its optimized architecture. Building on this material-level performance, an asymmetric supercapacitor (ASC) device is assembled using NCM-derived NCO@CNT as the positive electrode and ZIF-derived carbon as the negative electrode. This device demonstrates superior capacitance, excellent energy and power densities, and remarkable cycling stability. Altogether, these results highlight a rational dual-template strategy for engineering high-performance electrodes, paving the way for next-generation supercapacitors.