Preparation and Electro-catalytic Property of Self-supported Nickel Nanowire Array Electrode

A self-supporting nickel nanowire array (NNA) electrode was prepared by using the low-melting point alloy and porous polycarbonate template, and its catalytic performance toward hydrazine electro-oxidation was studied. SEM, XRD and TEM results show that the NNA electrode consists of a nickel plate and nickel nanowire arrays supported on it. The cotton-like surface of nickel nanowires provides the NNA electrode with the additional specific surface area. Cyclic voltammograms and chronopotential measurements show that when the concentration of hydrazine is 24. 6 mmol/L, the onset oxidation potential of the electrode is as low as -0. 25 V, and the oxidation current density is as high as 163 mA/cm(2). When the concentration of hydrazine is relatively low, the hydrazine electro-oxidation reaction and the Ni (OH)(2)/NiOOH conversion reaction of the electrode coexist. When the concentration of hydrazine reaches a relatively high level, only hydrazine electro-oxidation occurs. The reaction order of hydrazine species approximately equals to 1, and the reaction activation energy is 16. 13-21.24 kJ/mol. The integrated, open structure makes the NNA electrode show significantly better electrocatalytic perfkifmance than commercial nickel piece and nickel foam, and exhibit excellent stability.