Co₃S₄/NiS Nanowires Supported on Carbon Nanotube/Ni Foams for Applications as Asymmetric Supercapacitors and Alkaline Hydrogen Evolution

Self-supporting electrodes for supercapacitors and hydrogen evolution are essential for the development of clean electrochemical energy conversion and storage devices. Herein, a self-supporting Co3S4/NiS/CNT/NF electrode was constructed via Ni-induced self-assembly of a carbon nanotube (CNT) film on Ni foam followed by a Co3S4/NiS nanowire growth by a hydrothermal process. The electrode exhibits high specific capacitance (2889 F/g) and excellent rate capability. The Co3S4/NiS/CNT/NF//AC/NF asymmetric supercapacitor exhibited remarkable cycling stability and high energy density (83.3 Wh/kg at 500 W/kg). In addition, the Co3S4/NiS/CNT/NF electrode has a high durability and excellent hydrogen evolution activity (62 mV at 10 mA/cm2). The hierarchical three-dimensional network structure, the synergistic effect between Co3S4/NiS and CNTs, and the strong binding force favor fast electron/ion transfer, more exposed active sites, and fast faradic redox reaction, which are crucial for the excellent electrochemical performances of the electrode. This work provides insight into the design of multifunctional electrodes for electrocatalysis and energy storage applications.