Electrochemical supercapacitor behaviour of α-Ni(OH)2 nanoparticles synthesized via green chemistry route

Nickel hydroxide nanoparticles were synthesized at low temperature by simple green synthesis method using starch as the capping agent and water as the solvent. The structure and morphology of the nickel hydroxide particles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The prepared α-nickel hydroxide nanoparticles were found to be crystalline. The TEM images reveal the nanostructure of the nickel hydroxide. The average particle size of the nanoparticle estimated from the TEM measurement was 15 nm. Electrochemical investigations were carried out using cyclic voltammetry, charge–discharge and impedance analysis. From cyclic voltammetric studies, maximum specific capacitance of 534 F g−1 was obtained at a scan rate of 2 mV s−1.