Metal-organic framework-derived porous zinc oxide-carbon nanocomposites and nanoporous carbon as electrode materials for high-performance energy storage devices.

Electrochemical energy storage relies on high-energy and high-power devices with competitive practical efficiency. Metal-organic frameworks (MOFs) emerged as versatile sacrificial templates for porous metal oxides and carbonaceous composites with tunable architectures, high surface area, hierarchical porosity, and abundant electrochemically active sites. In this scenario, zinc 1,2,4,5-benzenetetracarboxylate (Zn-BTCA) was selected as the sole source material to derive both ZnO/C nanocomposites and nanoporous carbon (NPC) via a "One-to-Dual derivative" strategy at 900 °C under an Ar atmosphere. The as-derived ZnO/C nanocomposites contain ZnO nanoparticles and a porous carbon matrix, while hydrofluoric acid (HF) treatment removes ZnO to obtain NPC with a preserved porous framework. XRD, FTIR, and SEM analyses verified the crystal structure, chemical functionality, and morphology of the Zn-BTCA samples and the derived materials. The derived ZnO/C nanocomposites and NPC materials showed higher specific surface areas than the Zn-BTCA (3 : 2) precursor, with pore diameters in the mesoporous range. Subsequently, all Zn-BTCA samples and the derivatives obtained from Zn-BTCA (3 : 2) were electrochemically evaluated in a three-electrode assembly. The superior electrochemical performance of ZnO/C and NPC justified their selection as the positive and negative electrodes for hybrid device fabrication. The assembled ZnO/C‖NPC device achieved an excellent energy density (E d) of 144.8 Wh kg-1, a remarkable power density (P d) of 9350 W kg-1, and 90.11% capacity retention after 5000 cycles. Additionally, a quadratic semi-empirical model resolved the hybrid device kinetics, with 82.9% diffusion-controlled and 17.1% capacitive contributions at 30 mV s-1. This study shows that the MOF-derived materials possess strong capability for high-performance hybrid supercapacitor (HSC) applications.