LAUSR

The amino-functionalized bimetal NH2-NiCo-MOF nanosheet array is first fabricated on Ni foam substrates and then controllably transformed into oxygen vacancy bimetal oxide arrays by simply thermal annealing in air. This NiCo-based oxide array (NixCo3-xO4/NF) achieves high capacitance (2484 F g-1 at 1 A g-1), excellent rate performance (91.4%), and long cycling life when assessed as promising electrode material for supercapacitors. Notably, the existing oxygen vacancy in NixCo3-xO4 promotes the electrochemical performance of NixCo3-xO4/NF due to the enhancement of electrical conductivity and capture capability for OH-. In addition, the assembled asymmetric supercapacitor (ASC) device exhibits an excellent energy density of 39.3 W h kg-1 at a power density of 800.2 W kg-1, which still remains 32.2 W h kg-1 even at a high power density of 7994.5 W kg-1. Furthermore, a light-emitting diode can be lightened for more than 6 min, demonstrating a great potential for practical application of ASC devices. This work knocks on the door of a feasible strategy for designing and synthesizing 2D metal oxide nanosheet arrays with excellent electrochemical properties.