| 锌铈混合金属氧化物薄膜电化学沉积的研究 |
| Electrochemical Deposition of Mixed Zinc-Cerium Oxide Films |
|
| 摘要: 采用自制四电极体系，原位测量锌铈混合氧化物薄膜电沉积过程电极/溶液界面pH的动态变化。电极/溶液界面的pH-时间曲线表明，pH快速上升后达到平衡，且电沉积过电位越大，达到平衡pH值的时间越短，平衡pH值也越高。X射线粉末衍射(XRD)实验证明薄膜沉积物是由ZnO和CeO2组成。电感耦合等离子体(ICP)技术分析了不同电沉积电位、不同电沉积时间下电沉积产物中Ce(Ⅲ)/Zn(Ⅱ)的物质的量比，结果表明Ce(Ⅲ)/Zn(Ⅱ)的物质的量比随着pH值的升高而增加。依据Zn2+离子和Ce3+离子液相和固相中存在形态的热力学数据，计算了2种金属离子的条件溶解度随pH的变化曲线。结合实验测试数据和理论计算结果，讨论了电极表面金属氧化物的电化学沉积机理，并阐明了阴极表面混合金属氧化物的组成取决于液-固两相中金属离子存在形态的热力学性质。 |
| 关键词: 阴极电沉积 界面pH 氧化锌 氧化铈 |
| 基金项目: |
| Abstract: With a self-made four-electrode system, the pH changes at the electrode/solution interface were in-situ measured during the electrochemical deposition of mixed zinc-cerium oxide films. It could be given from the pH-time curves at the electrode/solution interface that the interfacial pH fast increased at the electro-deposition initial stage, then achieved a balance value. The results indicated that the larger the electrodeposition over-potential was, the less it took to achieve a pH balance value as well as the higher the pH balance value was. The electrodeposition films were composed of ZnO and CeO2 characterized by X-ray diffraction (XRD) patterns, and the Ce(Ⅲ)/Zn(Ⅱ) molar ratio of deposits were determined using inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The experimental results showed that the Ce(Ⅲ)/Zn(Ⅱ) molar ratio would increase with increasing both the interfacial pH and the electro-deposition time. The conditional solubilities of zinc and cerium ions as a function of pH values were calculated and plotted according to the thermodynamic constants for two metal ion species. Both the experimental data and the theoretical calculation results were used to discuss the reaction mechanism for electro-deposition of mixed cerium-zinc oxides on the cathodic surface and elucidate that the composition of mixed metal oxides would depend on the thermodynamic constants for two metal ion species. |
| Keywords: cathodic electro-deposition interfacial pH zinc oxide cerium oxide |
| |
| 摘要点击次数: 1524 |
| 全文下载次数: 1717 |
| 许胜霞,丁 翻,刘勇沼,张建民.锌铈混合金属氧化物薄膜电化学沉积的研究[J].无机化学学报,2012,28(9):1867-1872. |
| 查看全文 查看/发表评论 下载PDF阅读器 |
| Support information: |
|
|
|
|
|
|
