Funnel-shaped hierarchical NiMoO4@Co3S4 core-shell nanostructure for enhanced supercapacitor performance

Morphological matching plays a significant role in improving electrochemical properties of core-shell nanostructured as supercapacitor electrode. In this work, a hierarchical, vertically aligned funnel-shaped NiMoO4@Co3S4 core-shell nanostructure was designed by morphological matching for enhanced supercapacitor performance. The core electrode made of densely interconnected NiMoO4 nanosheets were prepared on nickel foam by hydrothermal synthesis, and the shell electrode made of loosely interconnected Co3S4 nanosheets with good conductivity were grown by electrochemical deposition to form a nanosheet-on-nanosheet core-shell nanostructure for improving the electrolyte penetration and storage, facilitating the charge transfer and diffusion. Consequently, the ultrathin nanosheets NiMoO4@Co3S4 core-shell electrode exhibits a remarkable specific capacitance as high as 359.31 mAh g−1 at current density 0.5 A g−1 (2589.6 F g−1 at current density 0.5 A g−1), and capacitance retention of 82.9% after 10,000 charge-discharge cycles. As positive electrode of NiMoO4@Co3S4 and negative electrode of activated carbon, a hybrid supercapacitor with an energy density of 33.37 W h kg−1 and a power density of 387.50 W kg−1 at current density 0.5 A g−1 was assembled. The excellent performance demonstrates that morphological matching is significant to construct core-shell nanostructure of supercapacitor electrode.