NiMoN催化电极材料的制备及其电解海水制氢性能

Preparation of NiMoN Catalytic Electrode Material for Hydrogen Production via Seawater Electrolysis

以四水合钼酸铵为钼源、六水合硝酸镍为镍源,采用水热法在泡沫镍基底上制备前驱体NiMoO4纳米棒阵列,然后通过热氮化法得到具有棒状阵列结构的NiMoN催化电极材料(简称NiMoN)。采用X射线衍射和扫描电子显微镜对NiMoN的物相结构和表面形貌进行表征;通过线性扫描伏安法、塔菲尔斜率、电化学阻抗谱等电化学测试手段,对NiMoN的半反应析氧(OER)、析氢(HER)以及全解水性能进行测试。结果表明,在碱性淡水和碱性模拟海水电解液中,NiMoN均显示了突出的OER活性,产生100.00 mA/cm^(2)的电流密度分别需要293、340 mV的过电位;NiMoN‐9具有较好的HER活性,在两种电解液中产生100.00 mA/cm^(2)的电流密度分别需要361、400 mV的过电位;NiMoN‐9具有良好的全解水性能,在两种电解液中产生100.00 mA/cm^(2)的电流密度所需电压分别为2.016、2.032 V,且可稳定运行55 h以上。

The precursor NiMoO4 nanorod arrays were prepared on nickel foam by a hydrothermal method using ammonium molydate tetrahydrate[(NH4)6Mo7O_(2)4·4H2O]as the Mo source and nickel nitrate hexahydrate[Ni(NO3)2·6H2O]as the Ni source,and subsequently were nitrogenized via a thermal treatment to obtain the NiMoN with rod‐like array structure.The phase structure and surface morphology of the catalytic electrode material were characterized by X‐ray diffraction(XRD)and scanning electron microscopy(SEM).Besides,the half‐reaction oxygen evolution reaction(OER),hydrogen evolution reaction(HER),and overall water electrolysis performance of the material were evaluated by adopting various electrochemical characterizations,including linear scanning voltammetry(LSV),Tafel slope,and electrochemical impedance spectroscopy(EIS).The test results show that the NiMoN‐9 catalytic electrode material has both high OER and HER activities.The OER overpotentials for this material to reach 100.00 mA/cm^(2) are only 293 mV and 340 mV respectively in alkaline fresh water and alkaline simulated seawater,while the corresponding HER overpotentials are 361 mV and 400 mV.In addition,the NiMoN‐9 material also exhibits good activities in both water electrolysis and seawater electrolysis with the cell voltages of 2.016 V and 2.032 V respectively to obtain 100.00 mA/cm^(2) as well as robust stabilities over 55 h.