摘要
通过电化学氧化共沉积技术在A1/导电涂层/α-Pb O2-Ce O2-Ti O2基体上,制备了A1/导电涂层/α-PbO 2-Ce O2-Ti O2/β-Pb O2-MnO 2-WC-Zr O2复合阳极材料。通过能量色散X射线光谱(EDXS)、阳极极化曲线、暂稳态极化曲线(Tafel)、交流阻抗谱(EIS)、扫描电子显微镜(SEM)以及X射线衍射(XRD)等方法研究电流密度对复合阳极材料的化学组分、电化学活性和稳定性的影响。研究结果表明:在电流密度为1 A/dm2条件下制备的A1/导电涂层/α-PbO 2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2复合材料具有最低的析氧过电位(0.610 V,条件:500 A/m2),最好的电化学活性,最长的使用寿命(360 h,条件:150 g/L H2SO4,2 A/cm2,40°C)以及最低的槽电压(2.75 V,条件:500 A/m2)。而且,随着电流密度的增加,涂层晶粒逐渐增大,MnO 2含量也逐渐降低,晶体结构几乎没有变化。
Al/conductive coating/α-Pb O2-Ce O2-Ti O2/β-PbO 2-MnO 2-WC-Zr O2 composite electrode material was prepared on Al/conductive coating/α-PbO 2-Ce O2-Ti O2 substrate by electrochemical oxidation co-deposition technique. The effects of current density on the chemical composition, electrocatalytic activity, and stability of the composite anode material were investigated by energy dispersive X-ray spectroscopy(EDXS), anode polarization curves, quasi-stationary polarization(Tafel) curves, electrochemical impedance spectroscopy(EIS), scanning electron microscopy(SEM), and X-ray diffraction(XRD). Results reveal that the composite electrode obtained at 1 A/dm2 possesses the lowest overpotential(0.610 V at 500 A/m2) for oxygen evolution, the best electrocatalytic activity, the longest service life(360 h at 40 °C in 150 g/L H2SO4 solution under 2 A/cm2), and the lowest cell voltage(2.75 V at 500 A/m2). Furthermore, with increasing current density, the coating exhibits grain growth and the decrease of content of Mn O2. Only a slight effect on crystalline structure is observed.
基金
Projects(51004056,51004057)supported by the National Natural Science Foundation of China
Project(KKZ6201152009)supported by the Opening Foundation of Key Laboratory of Inorganic Coating Materials,Chinese Academy of Sciences
Project(2010ZC052)supported by the Applied Basic Research Foundation of Yunnan Province,China
Project(20125314110011)supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China
Project(2010247)supported by Analysis&Testing Foundation of Kunming University of Science and Technology,China