NiCo₂O₄ nanowire arrays grown on Ni foam (NiCo₂O₄/NF) are synthesized by a simple template-free hydrothermal route followed by a thermal treatment in the air at 400 °C. The as-prepared Ni foam substrate exhibits homogeneous and porous nanowire arrays, which providing a number of active sites and electronic transmission channels for urea electrooxidation. The electroactivity of NiCo₂O₄/NF electrode toward the oxidation of urea in alkaline solution is evaluated using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) measurements. Results show that the as-obtained electrode delivers an outstanding electrocatalytic activity and stability for urea electrooxidation. The NiCo₂O₄/NF electrode delivers a low open potential at 0.19 V versus Ag/AgCl with a corresponding current density of 570 mA cm⁻² in 5 mol L⁻¹ KOH and 0.33 mol L⁻¹ urea electrolytes. Meanwhile, detailed investigation is made for the electrocatalytic oxidation of urea by varying several reaction parameters, such as scan rate, urea and KOH concentrations. Benefiting from the unique structure and synergistic effects of Ni and Co, the NiCo₂O₄/NF electrode exhibit superior electrocatalyst activity and is considered to be a promising candidate catalysis material for direct urea fuel cell.

通过简单的无模板水热途径，然后在空气中于400°C的热处理，合成在Ni泡沫上生长的NiCo ₂ O ₄纳米线阵列（NiCo ₂ O ₄ / NF）。所制备的Ni泡沫基材表现出均匀且多孔的纳米线阵列，其提供了用于尿素电氧化的许多活性位点和电子传输通道。NiCo ₂ O ₄的电活性使用循环伏安法（CV），计时电流法（CA）和电化学阻抗谱（EIS）测量，评估/ NF电极对尿素在碱性溶液中的氧化作用。结果表明，所获得的电极具有出色的电催化活性和对尿素电氧化的稳定性。NiCo ₂ O ₄ / NF电极相对于Ag / AgCl在0.19 V时提供低的开路电位，在5 mol L ^-1 KOH和0.33 mol L ^-1中的相应电流密度为570 mA cm ^-2尿素电解质。同时，通过改变一些反应参数，如扫描速率，尿素和KOH浓度，对尿素的电催化氧化进行了详细的研究。受益于Ni和Co的独特结构和协同作用，NiCo ₂ O ₄ / NF电极表现出优异的电催化剂活性，被认为是直接尿素燃料电池的有希望的候选催化材料。