Hierarchical collaborative architecture of MOF-derived cobalt phosphide-porous carbon conductive networks: enabling high-performance supercapacitor energy storage

Metal-organic framework (MOF)-derived composite nanostructures hold significant promise for high-performance supercapacitor (SC) electrodes due to their tunable porosity, abundant active sites, and compositional versatility. In this work, a hierarchical CoP-CNTs hybrid material was synthesized via a multi-step strategy using a ZIF-8@ZIF-67 core–shell precursor. The resulting structure integrates nitrogen-doped carbon frameworks, in situ grown carbon nanotubes (CNTs), and uniformly dispersed cobalt phosphide (CoP) nanoparticles, forming a well-defined hollow polyhedral architecture with a high specific surface area, interconnected mesopores, and electron-rich active sites. These structural features induce strong synergistic effects among the CNT network, CoP nanocrystals, and porous carbon matrix, collectively enhancing ionic transport, electronic conductivity, and redox activity. As a result, the CoP-CNTs electrode delivers a high specific capacitance of 590.8F g −1 at 0.5 A g −1 and maintains 96.8% of its capacitance at 5 A g −1 . Kinetic analysis reveals a hybrid charge storage mechanism dominated by surface-controlled pseudocapacitance. Assembled into a CoP-CNTs//AC asymmetric SC (ASC), the device achieves an energy density of 34.4 Wh kg −1 at 400  W kg −1 and 24.4 Wh kg −1 at 4000.5  W kg −1 , with 84.1% capacitance retention after 10,000 cycles. This work demonstrates the promise of MOF-derived CoP-CNTs hybrids for scalable, high-performance energy storage systems.