Facile synthesis of two-dimensional (2D) nanoporous NiO nanosheets from metal-organic frameworks with superior capacitive properties

In this work, we demonstrate the design and fabrication of porous nickel oxide nanosheets (NiO NSs). The Ni-based intermediates (Ni(H 2 O) 2 [Ni(CN) 4 ]· X H 2 O) are first prepared via an easy, environmentally friendly, and room temperature solution route. NiO NSs with well preserved morphology are then obtained by annealing treatment of Ni-based intermediates at 300 °C in air. Due to the highly porous nanostructure, NiO NSs have a relatively high specific surface area of 118.2 m 2 g −1 . When evaluated for capacitive performance, the NiO NSs deliver a high specific capacitance of 527.1 F g −1 at 1 A g −1 , and retain a good specific capacitance retention of about 80.2% even at a high current density of 5 A g −1 after 500 charge-discharge cycles. 2D nanoporous NiO nanosheets were synthesized from metal-organic frameworks as precursors using a facile method, which exhibited superior capacitive properties.