Fe/Co-doped MOF-derived nanoporous carbon in wood-based carbon electrodes for high-performance supercapacitors

A Fe/Co-doped zeolitic imidazolate framework-8 (ZIF-8) is synthesized in situ on porous carbonized wood, and high-performance composite electrodes are subsequently prepared through heat treatment. The simultaneous doping of Fe and Co can synergistically modulate the microstructures, nanoporous architectures, and hydrophilic properties of the carbon materials derived from metal-organic frameworks (MOFs), thereby enhancing their specific capacitance and energy density. Furthermore, the superior capacitive performance of Fe/Co-doped MOF-derived carbon on porous carbonized wood (Fe-Co/MC@PCW) is predicted through first-principles density functional theory calculations, which are based on the detailed analysis of band structure and surface adsorption characteristics. The composite electrode demonstrated a specific capacitance of 342 F g −1 (6.84 F cm −2 ) at 5 mA cm −2 . Correspondingly, a symmetric supercapacitor fabricated with this electrode achieved a specific capacitance of 141 F g −1 (2.82 F cm −2 ) under identical conditions, yielding an energy density of 19.58 Wh kg −1 and a power density of 125 W kg −1 . Notably, the electrode maintains exceptional capacitance retention, demonstrating only a minor reduction to 96 % after 15,000 cycles, even at 30 mA cm −2 . These results underscore the potential of integrating MOFs with wood-based carbon electrodes for the development of advanced energy storage systems.