In-situ construction of heterostructure (Ni, Co)Se nanoarrays derived from cone-like ZIF-L for high-performance hybrid supercapacitors.

The construction of heterostructure could enhance the electron transfer efficiency and increase the number of active sites, which can further develop high-performance electrode materials of supercapacitors. Herein, (Ni, Co)Se nanorod arrays were prepared based on the NiCo-LDH derived from a conical ZIF-L. Significantly, the single nanorod is composed of interconnected NiSe and CoSe nanoparticles, the heterostructure can expose higher conductivity, more sufficient redox reaction active sites and larger specific surface area. The as-obtained CF@(Ni, Co)Se achieved a high specific capacity of 188.8 mAh g at the current density of 1.0 A g and an outstanding cycling stability with a high capacity retention of 90% after 8000 cycles. Finally, an hybrid supercapacitor device composed of activated carbon (AC) as negative electrode and CF@(Ni, Co)Se as positive electrode was designed, which revealed an ideal voltage window of 0-1.6 V and exhibited a great energy density of 36.02 Wh kg at the power density of 800 W kg, such surpassing energy storage characteristics evidently testify that (Ni, Co)Se nanorod arrays can be as the potential electrode material to promote the development of high-performance supercapacitors.