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(H2O)2[Ni(CN)4]·XH2O) 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 m2 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.