Facile synthesis of nanoflower-like NiMoO4/NiO structures for supercapacitive electrode materials

Abstract

Unique NiMoO₄/NiO nanocomposites (NCs) are synthesized by a straightforward hydrothermal process followed by annealing, using Ni(NO₃)₂·6H₂O and Na₂MoO₄·2H₂O as sources of nickel and molybdenum, with urea playing a key role in determining the composition. A systematical characterization explores the variations rule of effect of urea levels on the chemical composition, crystalline structure, and electrochemical characteristics of these nanocomposites. Due to its unique design, the NiMoO₄/NiO nanocomposites present a wealth of microporous active sites. Utilized as electrode materials, these nanocomposites demonstrate superior electrochemical properties, attaining a specific capacitance value of 1294.4 F g⁻¹ when tested at a current density of 1 A g⁻¹. They also maintain 86.32 % of their initial capacitance after 5000 charge-discharge cycles. In a distinctive asymmetric supercapacitor setup, labeled NiMoO₄/NiO//AC, the peak energy density achieved is 14.39 Wh kg⁻¹ at a power density of 264.67 W kg⁻¹, with a retention of 69.97 % capacity after 5000 cycles, illustrating its long-term cycling stability. This research underscores the transformative potential of NiMoO₄/NiO nanocomposites in advancing energy storage solutions.