Effects of complex agents on the anodic deposition and electrochemical characteristics of cobalt oxides
Effects of complex agents on the anodic deposition and electrochemical characteristics of cobalt oxides
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DOI：
10.1016/j.electacta.2007.09.060
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发表时间：
2008
影响因子：
6.6
通讯作者：
Chi-Chang Hu;Tung-Yu Hsu
中科院分区：
文献类型：
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作者：
Chi-Chang Hu;Tung-Yu Hsu
CoCl2·6H2O 中氧化钴的阳极沉积速率受到沉积溶液中添加的络合剂类型（乙酸根离子 (AcO−)、柠檬酸根离子、EDTA）的强烈影响。通过线性扫描伏安法 (LSV) 检测，CoCl2·6H2O 的氧化电位从约负移。通过添加 AcO−、柠檬酸根离子和 EDTA，分别将 1.1V 降至约 0.8、0.5 和 0.2V。研究发现，氧化钴的沉积速率不仅取决于 Co 和配体之间的配位强度，还取决于电子转移后 Co-L 配合物（L：配体）转化为氧基-羟基-Co 物质的转化率。通过 X 射线光电子能谱 (XPS)、扫描电子显微镜 (SEM)、开路电位随时间和循环伏安分析检查所得 Co 氧化物的结构和电化学特性，也受到络合剂变化的影响。当 Co 氧化物从含有 AcO− 的前驱体溶液中沉积时，沉积速率最高，同时也表现出最高的比电容 (ca)。 230Fg−1 在所有 Co 氧化物沉积物中（氧化物负载量≥0.05mgcm−2），证明其在电化学超级电容器中最有前景的应用。
The anodic deposition rate of cobalt oxide from CoCl2·6H2O is strongly affected by the type of complex agents (acetate ion (AcO−), citrate ion, EDTA) added into the deposition solutions. The oxidation potential of CoCl2·6H2O, examined by linear sweep voltammetry (LSV), is negatively shifted from ca. 1.1V to about 0.8, 0.5, and 0.2V by adding AcO−, citrate ion, and EDTA, respectively. The deposition rate of cobalt oxide is found to depend not only on the coordinating strength between Co and ligands but also on the conversion rate of the Co–L complexes (L: ligand) into the oxy-hydroxyl-Co species after electron transfer. The textural and electrochemical characteristics of resultant Co oxides, examined by X-ray photoelectron spectroscopic (XPS), scanning electron microscopic (SEM), open-circuit potential versus time, and cyclic voltammetric analyses, are also influenced by varying the complex agents. The deposition rate is the highest when the Co oxide is deposited from the precursor solution containing AcO−, which also exhibits the highest specific capacitance of ca. 230Fg−1among all Co oxide deposits (as the oxide loading ≥0.05mgcm−2), demonstrating its most promising applicability in the electrochemical supercapacitors.