Effects of deposition temperature and annealing temperature on the morphology and electrochemical capacitance of Ni(OH)2 thin films

In this paper, we report 3D nickel (II) hydroxide thin films with porous nanostructures prepared on Ni foam by direct current electrodeposition from aqueous solution of Ni(NO3)2 through basic chemicals. The effect of deposition temperature on Ni(OH)2 thin film morphology is examined by field emission scanning electron microscopy, which is found to have significant influence on capacitance performance of Ni(OH)2 thin films. Moreover, the effect of annealing temperature on electrochemical capacitance and long-time stability of Ni(OH)2 thin films is investigated. An optimum-specific capacitance value of 2,447 farads g−1 is obtained for Ni(OH)2 thin film deposited at 20 °C and annealed at 100 °C.