Abstract

Some Co and Co-X (x = B, s, Fe) composite has high discharge capacity and good cycling stability. Due to Co series materials′ high theoretical specific capacity, they are widely used in electrocatalysis, electrochemical analysis, alkaline battery and super capacitor and other fields. However, the research on Co-X composites is not comprehensive enough, and the properties of some composite materials produced by compounding the metals with Co using some particular methods have not been systematically analyzed. Focused on Co-X (X=Fe, Ni, V) mixed metal oxides, this experiment used one-step hydrothermal method and carried out systematic researches on their oxygen evolution properties.

First of all, the crystal structure and morphology of the material were characterized by powder X-ray diffraction (XRD), and scanning electron microscopy (SEM) analysis with the catalytic current of materials, active surface area and charge transfer resistance, Tafel slope and stability being investigated by linear sweep and cyclic voltammetry (CV), and electrochemical impedance (EIS) test, Tafel test, constant potential test at the mean time. The reaction time of this experiment was fixed to 12h, we then made the material selection for optimal Co-X (X=Fe, Ni, V) composite under the condition of the concentration ratio of 1:1:1 and the reaction temperature of 180 degrees Celsius. Then researches were done by optimizing the reaction temperature and the concentration ratio within the fixed 12h reaction time, the results of which turned out that under the condition of the reaction temperature of 100 DEG C and concentration ratio of 2:1:1, Co:Fe:V composite can exhibit much better catalytic performance and the catalytic current can reach up to 65 mA.

摘要

一些Co和Co-X(X=B、S、Fe)复合材料具有较高的放电容量和良好的循环稳定性，由于Co系列材料具有较高的理论比容量而在电催化、电化学分析、碱性电池以及超级电容器等领域得到广泛应用。但是对Co-X复合材料的研究还不够全面，某些金属在某些特定的方法下与Co合成的材料的性能还未得到系统的分析。本实验采用一步
水热法针对Co-X(X=Fe、Ni、V)混合金属氧化物，并系统的对其析氧性能进行研究。

首先，分别通过粉末X射线衍射（XRD）和扫描电镜（SEM）分析对材料进行晶型结构和形貌结构进行表征，同时也采用线性扫描、循环伏安法（CV）、电化学交流阻抗（EIS）测试、Tafel测试、恒电位测试法对材料的催化电流、活性面积、电荷传递阻抗、Tafel斜率和稳定性进行了系统考察。本实验的反应时间固定为12h，我们在浓度比为1:1:1和反应温度180℃的条件下对Co-X(X=Fe、Ni、V)材料进行选材，得到最优的一种材料组合Co-Fe-V复合材料。然后在反应时间12h下优化了材料的反应温度和反应比例，结果表明在反应温度为100℃，Co:Fe:V浓度比为2:1:1的复合材料催化性能较优，其催化电流可达到65 mA。