Metal-organic framework templated fabrication of Cu7S4@Ni(OH)2 core-shell nanoarrays for high-performance supercapacitors
Well-controlled core-shell nanostructural arrays and rational combination of hybrid electrochemical active materials as promising candidate electrodes for supercapacitors are highly attractive and still of great challenge. In this work, the ultrathin Ni(OH)2 nanosheets as “shell” anchored on Cu7S4 nanorods as “core” to form core-shell hybrid nanoarrays on copper foam, which was firstly fabricated by a facile metal-organic framework templated synthetic strategy with a three-step procedure of in situ interface growth, sulfurization and hydrothermal synthesis. The core-shell Cu7S4@Ni(OH)2/CF hybrid nanoarrays as binder-free electrode displays a high specific capacitance of 1072.5 F g-1 (482.6 C g-1) at a current density of 1 A g-1, superior rate capacity (86.4% at 10 A g-1) and the outstanding cycling stability of 94.5% capacitance retention after 10000 cycles. What’s more, the assembled asymmetric supercapacitor device based on Cu7S4@Ni(OH)2/CF as positive electrode and activated carbon (AC) as negative electrode offers a high energy density of 52.5 Wh kg-1 at the power density of 750 W kg-1 with decent cycling stability. This strategy can extend to form other unique copper sulfides based core-shell nanoarrays architectures with the enhanced electrochemical activity for high-performance energy storage devices.