Synthesis and supercapacitive performance of CuO/Cu 2 O nanosheet arrays modified by hydrothermal deposited NiOOH

Binder-free, high-performance electrode materials play a critical role for supercapacitors. In this paper, through the electrochemical anodization process, ordered CuO/Cu 2 O nanosheet arrays (NSAs) were successfully in situ fabricated on copper foil, which could be directly adopted as the current collector. Then, NiOOH was introduced for the further modification of CuO/Cu 2 O arrays via a facile hydrothermal deposition treatment using nickel nitrate as precursor. The as-fabricated NiOOH@CuO/Cu 2 O composite nanosheet arrays exhibit an excellent areal capacitance of 1206 mF cm −2 at a current density of 1 mA cm −2 in 2 M KOH aqueous solution with an outstanding long-term cycling stability, with 84.6% of initial capacitance after 3000 charge/discharge cycles. The facile, cost-effective, and controllable fabrication route and the robust supercapacitive activity suggest that the NiOOH@CuO/Cu 2 O composite nanosheet arrays could be a promising candidate electrode material for high-performance supercapacitors.