电沉积掺杂二氧化铅表面的研究进展

来源期刊:中国有色金属学报2008年第9期

论文作者:陈步明 郭忠诚 杨显万 张杰磊 龙晋明

文章页码:1712 - 1720

关键词:二氧化铅;电沉积;掺杂离子;掺杂颗粒;催化活性;脆性

Key words:PbO2; electrodeposition; doping-ions; doping-particles; catalytic activity; brittleness

摘    要:二氧化铅作为阳极由于具有高的催化活性、高的析氧过电位和化学惰性而受到关注。电沉积二氧化铅时,添加某些外来离子或颗粒能改善其电催化活性和稳定性,这些离子和颗粒主要包括Bi3+、F-、Fe3+、Co2+、Ce3+、Ru3+、As3+、Co3O4、RuO2、PbO2、A12O3和TiO2等。阐述了二氧化铅的应用领域,讨论了电沉积掺杂二氧化铅的制备方法及其影响因素;针对二氧化铅固有的催化活性和脆性的缺陷,评述了掺离子和固体颗粒的二氧化铅镀层的优缺点。结果表明:掺杂Bi3+、F-、Ce3+、Ru3+和Ag+离子能提高二氧化铅的催化活性;掺杂In3+、PO43-和As3+能抑制二氧化铅的晶核形成;提出外来离子掺杂在二氧化铅晶格缺陷中的几种模式:可变价的金属离子取代Pb4+,并且自身被氧化成高价的金属离子掺杂在二氧化铅镀层中,这些金属离子是Bi3+、Ce3+、Ru3+、Ag+、Co2+和As3+;在F-修饰的二氧化铅中,F-离子替代两个OH-离子;Fe3+分别在低温和高温下取代Pb2+和Pb4+;F-离子分别与Fe3+或Co2+形成协同效应。复合镀层的电催化作用与掺杂的催化粒子类型及其应用领域有关,例如:PbO2+RuO2复合镀层在硫酸溶液中显示最好的催化活性;PbO2+Co3O4在氢氧化钠溶液中具有最好的电催化活性;当然,复合镀层的表面粗糙度的影响不能完全忽视。掺杂PTFE和TiO2颗粒能显著的降低二氧化铅镀层的脆性。展望了掺杂二氧化铅镀层的发展趋势。

Abstract: A great interest was attracted in the improvement of lead dioxide as anode material owing to its high electriconductivity, high oxygen overpotential and chemiinertness. During electrodepositing pure lead dioxide, the electrocatalytic activity of PbO2 electrodes, as well as their stability, can often be considerably enhanced by the incorporation of some foreign ions or fine particles added to the electrodeposition solution. The application fields of PbO2 were elucidated, and the preparation methods and influencing factors of the undoped-PbO2,ion-doped PbO2 and matrix composites in the absence or presence of cations, anions and suspended particles, including Bi3+, F-, Fe3+, Co2+, Ce3+, Ru3+, As3+, Co3O4, RuO2, PbO2, A12O3, TiO2 and so on, were reported and discussed. To overcome the intrinsic shortcomings of the catalytic activity and brittleness of PbO2 coatings, this review was also extended to the advantages and disadvantages by doping ion and particles. It is shown that the electrocatalytic activity of PbO2 coatings can be greatly enhanced by incorporation of some ions, such as Bi3+, Ce3+, Ru3+, Ag+,Co2+, F-, Fe3+,F-+Fe3+and F-+Co2+, while In3+, PO43- and As3+ decrease the rate of deposition of lead dioxide. Several models propose that the incorporation of the foreign species in PbO2 occur at defect sites: the Pb(Ⅳ) is substituted with the altervalent metallic cations followed by oxidation of the incorporated the altervalent metallic cations to highvalent, for example like Bi3+, Ce3+, Ru3+, Ag+,Co2+ and As3+, and F- replaces OH groups while Fe3+ can replace Pb2+ or Pb4+ at low and high temperature, respectively. There is a synergic effect of the F and Fe or Co dopants. The electrocatalytic function of the composite oxide layers is probably related to the catalytic particles and the application range of the materials, for example, the PbO2+RuO2 layers exhibit fairly high electrocatalytic activity for the oxygen evolution reaction in H2SO4 solution, and the PbO2+Co3O4 layers exhibit the best electrocatalytic activity in NaOH solution. However, the possible effect of surface roughness of the PbO2-matrix composites cannot be entirely neglected. The brittleness of PbO2 coatings is greatly improved with doping PTFE or TiO2 particles. In addition, the developing tendency of the doped coating of lead dioxide was prospected.

基金信息:教育部全国百篇优秀博士学位论文作者专项基金资助项目

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