物理化学学报 >> 2007, Vol. 23 >> Issue (10): 1515-1519.doi: 10.3866/PKU.WHXB20071006

研究论文 上一篇    下一篇

PbO2阳极在硫酸溶液中的析氧失活行为

曹江林; 吴祖成; 李红霞; 张鉴清   

  1. 浙江大学环境工程系, 杭州 310027; 天津大学环境科学与工程学院, 天津 300072; 浙江大学化学系, 杭州 310027; 中国科学院金属研究所, 金属腐蚀与防护国家重点实验室, 沈阳 110016
  • 收稿日期:2007-02-02 修回日期:2007-07-03 发布日期:2007-10-01
  • 通讯作者: 吴祖成 E-mail:wuzc@zju.edu.cn; shjzhcaojl@163.com

Inactivation of PbO2 Anodes during Oxygen Evolution in Sulfuric Acid Solution

CAO Jiang-Lin; WU Zu-Cheng; LI Hong-Xia; ZHANG Jian-Qing   

  1. Department of Environmental Engineering, Zhejiang University, Hangzhou 310027, P. R. China; School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, P. R. China; Department of Chemistry, Zhejiang University, Hangzhou 310027, P. R. China; 4State Key Laboratory for Corrosion and Protection of Metals, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China
  • Received:2007-02-02 Revised:2007-07-03 Published:2007-10-01
  • Contact: WU Zu-Cheng E-mail:wuzc@zju.edu.cn; shjzhcaojl@163.com

摘要: 采用热分解鄄电镀法制备了以Sb 掺杂SnO2(Sb-SnO2)为底层的Ti 基PbO2阳极(Ti/PbO2). 采用加速电解寿命测试、电化学阻抗谱、XRD、SEM-EDX 等技术, 研究了Ti/PbO2阳极在硫酸溶液中的电解失效行为和机制.结果表明,在新制备的PbO2镀层中, 由于氧空位的存在, PbO2镀层的内应力表现为拉应力, 随着电解的进行, 阳极表面生成的活性氧原子在向基底扩散的过程中, 将Pb3+态氧化为Pb4+态, 逐渐占据镀层内作为自由电子施主的氧空位, 这不仅导致镀层的导电性能下降, 同时使镀层的应力逐渐由拉应力转变为压应力, 镀层性质逐渐劣化. 这一过程基本结束时,活性氧原子才大量扩散至Ti基底导致基底的钝化, 在Ti 基底和镀层界面出现显著的界面应力, 在界面应力和镀层内压应力的共同作用下, 阳极出现鼓泡、脱落, 迅速进入失活阶段.

关键词: 失活, PbO2阳极, 内应力

Abstract:

Ti-substrate PbO2 (Ti/PbO2) anodeswith Sb-doped SnO2 interlayer were prepared by thermal decomposition-electroplating technique. The behavior and mechanism of the inactivation of Ti/PbO2 anodes were studied by the
accelerated life test, electrochemical impedance spectrum, XRD and SEM-EDX. The results showed that the inactivation of Ti/PbO2 anodes was a developing process. During oxygen evolution, partial active oxygen atoms produced as intermediate product diffuse toward Ti substrate, and they oxidize Pb3+ to Pb4+ in the PbO2 coating to occupy gradually the oxygen vacancies as free electron donors. This results in not only the decrease of conductivity but also a change of intrinsic stresses from tensile stresses to compressive stresses. When the process was finished on the whole, large numbers of active oxygen atoms began to diffuse to Ti substrate. The oxidation of Ti substrate led to
the production of an interfacial stresses. Under the effects of compressive intrinsic stresses and interfacial stresses, PbO2 coating knobs out, subsequently flakes off and Ti/PbO2 anodes become inactive rapidly.

Key words: Inactivation, PbO2 anode, Intrinsic stress

MSC2000: 

  • O646