镍铁双氢氧化物的响应曲面法优化生长和电催化析氧性能研究

Optimization of Growth and Electrocatalytic Oxygen Evolution of Nickel-Iron Dihydroxide by Response Surface Method

采用腐蚀工程制备了层状镍铁双氢氧化物电催化剂,利用X光衍射、场发射扫描电镜、高分辨透射电镜和光电子能谱等对样品物理化学特性进行了表征,采用线性伏安特性曲线、塔菲尔曲线、电化学阻抗谱、循环伏安特性以及恒电流下电势-时间曲线对样品电催化析氧特性进行了详细分析。在单因子实验的基础上,以50 mA·cm^(-2)对应析氧过电位为响应因子,用响应曲面法对影响催化剂性能的主要因素进行了优化,建立了泡沫镍铁腐蚀后析氧过电位的多项式模型,得出的优化制备条件为腐蚀温度80℃、时间9 h、NiSO_(4)浓度9 mmol·L^(-1)。在该条件下制备的样品在10 mA·cm^(-2)下的过电位为200 mV,Tafel斜率为52.5 mV·dec^(-1);50 mA·cm^(-2)电流密度下经过48 h连续测试,其OER催化活性仍能保持在95%,比起商用RuO_(2)电极显示出优良的电催化活性。

The layered nickel-iron dihydroxide electrocatalysts were prepared by corrosion engineering.The physicochemical properties of the samples were characterized by X-ray diffraction,field emission scanning electron microscopy,high resolution transmission electron microscopy and photoelectron spectroscopy.Linear voltammetry characteristic curve,Tafel curve,electrochemical impedance spectrum,cyclic voltammetry cha-racteristic and constant-current potential-time curve were used to analyze the electrocatalytic oxygen evolution characteristics of samples in detail.On the basis of single factor experiment,with 50 mA·cm^(-2)corresponding to the oxygen evolution potential for response factor,by using the response surface method on the main factors affecting the catalyst performance is optimized,established the oxygen evolution after the foam nickel iron corrosion potential of the polynomial model.And the corrosion temperature of 80℃,time of 9 h,NiSO_(4)concentration of 9 mmol·L^(-1)are the optimization of the preparation conditions.The sample prepared under this condition has an overpotential of 200 mV at 10 mA·cm^(-2)and a Tafel slope of 52.5 mV·dec^(-1).After 48 h continuous testing at 50 mA·cm^(-2)current density,the OER catalytic activity remaines at 95%,showing better electrocatalytic activity than the commercial RuO_(2)electrode.