Advanced 3D hierarchical composite electrode materials for supercapacitors: Biomass derived carbon doped CoMoO₄@NiCo₂O₄

Carbon-doped CoMoO4@NiCo2O4 on nickel foam (C-CoMoO4@NiCo2O4@Ni foam) electrode is prepared by twostep hydrothermal method. Phyllanthus reticulates extract is used as carbon source and reducing agent for preparation of CoMoO4@NiCo2O4. The XRD and FE-SEM analyses have confirmed the formation of phases and the hierarchical structure of this electrode. Moreover, this C-CoMoO4@NiCo2O4@Ni foam electrode has been directly employed in supercapacitor applications. Impressively, it exhibits a high specific capacitance of 3130 F g(-1) at a current density of 1 A g(-1), surpassing the performance of both C-CoMoO4@Ni foam (2482 F g(-1)) and CNiCo2O4@Ni foam electrodes (1884 F g(-1)). Remarkably, the C-CoMoO4@NiCo2O4@Ni foam electrode maintains good rate performance, with a 60 % capacity retention after 10,000 cycles at a current density of 100 A g(-1). This outstanding performance can be attributed to the distorted array of CoMoO4 nanosheets and NiCo2O4 nanoflakes, which significantly enhance the exposure of active sites and provide a larger surface area for redox reactions. In summary, the C-CoMoO4@NiCo2O4@Ni foam electrode offers exceptional specific capacity, long-term cycling stability, and excellent rate performance, making it a promising choice for various energy storage applications, including supercapacitors.