Flower-like nickel‑cobalt-layered double hydroxide nanosheets deposited on hierarchically porous graphitic carbon nitride for enhanced electrochemical energy storage

Abstract

Herein, flower-like nickel‑cobalt-layered double hydroxide nanosheets (f-NiCo-LDH) were deposited on porous graphitic carbon nitride (g-CN) by using F127 as the structure modulating agent and through a facile refluxing method. Benefiting from the binary composition and hierarchically porous structure, the optimized f-NiCo-LDH/g-CN2 composite delivered high specific capacitance of 2933.3 F g−1 at 0.5 A g−1, high rate capability of 410 F g−1 at 50 A g−1, and stable cycling behavior with 75.3% capacitance retention after 7000 cycles. When the f-NiCo-LDH/g-CN2 composite was assembled as cathode in asymmetric capacitor with activated carbon as the anode, the hybrid supercapacitor could deliver a maximum energy density of 52.7 Wh kg−1 at the current of 0.5 A g−1. Therefore, the superior capacitive properties as well as the simple preparation strategy of the as-prepared f-NiCo-LDH/g-CN2 material indicate its promising application as high-performance electrode for supercapacitors.