Preparation and supercapacitor application of the single crystal nickel hydroxide and oxide nanosheets

摘要

The single crystalline Ni(OH)_2 nanosheets were synthesized by a simple chemical precipitation method using nickel chloride as precursors and ammonia as precipitating agent. The Ni(OH)_2 nanosheets were successfully converted to NiO nanosheets via calcination under appropriate conditions. Analytical methods such as X-ray diffraction (XRD) spectra, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), and Fourier transformed infrared (FTIR) spectra were employed to characterize the morphology and microstructure of the final products. The experimental results revealed that Ni(OH)_2 nanosheets were shape-preserved transformed to NiO nanosheets at 250℃ for 24 h. Ni(OH)_2 and NiO nanosheets were directly functionalized as supercapacitor electrodes for potential energy storage applications, whose charge-discharge properties, electrochemical impedance spectra, cyclic voltammetry, and cycle performance were examined. The experimental results show that the single-crystalline NiO nanosheets are a promising candidate for the supercapacitor electrode. They exhibit a high specific capacitance, prompt charge/discharge rate.