Flower-like Co nano-particles deposited on Ni foam substrate as efficient noble metal-free catalyst for hydrazine oxidation

Ni foam supporting flower-like Co nano-particles (Co NFs/Ni foam) are successfully synthesized by a simple electrochemical method. The electrodes are characterized by scanning electron microscopy equipped with an energy dispersive X-ray spectrometer, and X-ray diffractometer. Without any conducting carbons and polymer binders, the 3D electrode with a unique structure is directly used as the noble metal-free catalyst for hydrazine oxidation and the catalytic performance is evaluated by voltammetry and chronoamperometry. The Co NFs/Ni foam electrode exhibits excellent catalytic performance and superior stability for hydrazine electrooxidation in alkaline media. In the solution of 1.0 mol L-1 NaOH + 30 mmol L-1 N2H4, the oxidation current density at -0.8 V is 140 mA cm(-2) for the Co NFs/Ni foam electrode, and it is only 42 mA cm(-2) for the Pt/Ni foam electrode. Also, the onset potential for Co NFs/Ni foam electrode can reach to -1.06 V (only -0.72 V for Ni foam), suggesting that the high cell voltage of DHFC with Co NFs/Ni foam anode. These merits are benefitting from the unique 3D structure which can ensure high utilization of catalysts. (C) 2015 Elsevier B.V. All rights reserved.