Mixed metal-organic framework-derived NiO/V2O3/C heterojunction nanostructures for high-performance hybrid supercapacitors

Abstract

Transition metal oxides with low cost and good redox properties are excellent candidates for supercapacitor electrode materials. Herein, we present the synthesis of MOF-derived dual transition metal oxide heterojunction nanostructures (NiO/V₂O₃/C) via hydrothermal and thermal processes. The influence of different ligands and thermal conditions on the electrochemical performance of the resulting materials was systematically examined. The NiO/V₂O₃/C (NVI-500) electrode material, comprising isonicotinic acid as a ligand, exhibits distinctive heterojunction characteristics at the nanoparticle interfaces, a substantial specific surface area, and synergistic effects that collectively contribute to an exceptional specific capacitance of up to 855 F g^-1 at 1 A g^-1. Encouragingly, the capacity conservation rate of NVI-500 is 68.1% after 3000 cycles (10 A g^-1). Furthermore, the constructed asymmetric supercapacitors demonstrated excellent energy density (26.6 Wh kg^-1) and power density (400 W kg^-1) with an initial capacitance retention of 83.8% after 9000 cycles. This finding serves to demonstrate that the construction of non-homogeneous transition metal oxides using MOFs as precursors is indeed a feasible strategy.