Microwave-assisted synthesis of 3D flowerlike α-Ni(OH)2 nanostructures for supercapacitor application

Abstract

Three-dimensional flowerlike a-Ni(OH)2 nanostructures were successfully synthesized by the microwave-assisted reflux as short as 30 min. The crystalline structure and morphology of the products were characterized by X-ray diffraction, N2 adsorption-desorption isotherms, field emission scanning electron microscopy, and transmission electron microscopy. The a-Ni(OH)2 nanostructure shows a large surface area of 173 m2 g-1 and narrow mesopore distribution. The electrochemical properties of the as-prepared a-Ni(OH)2 as an electrode material for supercapacitor were investigated by cyclic voltammetry and galvanostatic charge-discharge measurements in 6 mol/L KOH electrolyte. The a-Ni(OH)2 nanostructure shows a maximum specific capacitance of 2030 F g-1 at a current density of 1 A g-1 and exhibits excellent rate capability. These results suggest that it is a promising electrode material for supercapacitor application.