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

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-CN 2 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-CN 2 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-CN 2 material indicate its promising application as high-performance electrode for supercapacitors. By using P123-templated porous g-CN as the loading substrate and F-127 as the structure-directing agent, f-NiCo-LDH/g-CN 2 composite with flower-like morphology and enhanced conductive properties was successfully prepared. The typical hierarchically porous structure and optimized composition endow the composite material with high and stable capacitive properties. • P123-templated hierarchically porous g-CN with high nitrogen-doping content was used as the loading substrate for NiCo-LDH. • CN could bring the composite material with improved conductivity. • G-CN with high surface charge density and large specific surface area could improve the loading amount of NiCo-LDH. • Guided by F-127, the NiCo-LDH nanosheets grown on g-CN exhibit flower-like morphology with abundant macro- and mesopores. • The composite with optimized composition and porous structure delivers high and stable capacitive properties.