Abstract:

The NiCo₂O₄ nanorods were prepared by a hydrothermal method with nickel nitrate hexahydrate （Ni(NO₃)₂·6H₂O） as the nickel source,cobalt nitrate hexahydrate （Co(NO₃)₂·6H₂O） as the cobalt source,and urea as the precipitant.Then the above NiCo₂O₄ nanorods were immersed into the RuCl₃ solution to obtain the NiCo₂O₄/Ru composite catalyst by reduction.Testing technologies such as X?ray diffraction (XRD) and scanning electron microscopy (SEM) were adopted to characterize the phase structure and morphology of this composite catalyst, and its catalytic performance toward the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) was investigated by electrochemical methods such as linear scan voltammogram (LSV) and electrochemical impedance spectroscopy (EIS). Moreover, the NiCo₂O₄/Ru composite catalyst was used as the anode to assemble the Zn?air battery, whose open circuit voltage,charge and discharge performance,and cycle stability were evaluated by a LANHE test system. The results show that the NiCo₂O₄/Ru composite catalyst has high ORR/OER bifunctional catalytic activity with an OER overpotential of 420 mV at 10.0 mA/cm² and an ORR half?wave potential of 0.77 V.The assembled Zn?air battery also exhibits an open circuit voltage of 1.37 V, a maximum power density of 143 mW/cm²,as well as robust cycle stability for 50 hours.

Key words: Composite catalyst, Oxygen reduction reaction, Oxygen evolution reaction, Electrocatalysis, Zn?air batteries

摘要：

以六水合硝酸镍（Ni(NO₃)₂·6H₂O）为镍源、六水合硝酸钴（Co(NO₃)₂·6H₂O）为钴源、尿素为沉淀剂，采用水热法制备NiCo₂O₄纳米棒，然后浸渍还原RuCl₃，得到了NiCo₂O₄/Ru复合催化剂。利用X射线衍射（XRD）、扫描电子显微镜（SEM）等测试技术，对复合催化剂的物相、形貌进行了表征。通过线性扫描伏安法（LSV）、电化学阻抗谱（EIS）等电化学测试手段，对催化剂的氧还原反应（ORR）和析氧反应（OER）的催化性能进行了研究。将NiCo₂O₄/Ru复合催化剂作为正极组装锌空电池，使用蓝电电池测试仪评价了其开路电压、充放电性能和循环稳定性等指标。结果表明，NiCo₂O₄/Ru复合催化剂在电流密度为10.0 mA/cm²时，析氧过电位为420 mV，氧还原半波电位为0.77 V，且具有较高的ORR/OER双功能催化活性；由NiCo₂O₄/Ru复合催化剂组装的锌空电池开路电压为1.37 V，峰值功率密度为143 mW/cm²，且能稳定循环50 h。

关键词: 复合催化剂, 氧还原反应, 析氧反应, 电催化, 锌空电池