(昆明理工大學(xué) 材料與冶金學(xué)院，昆明 650093)
摘 要: 二氧化鉛作為陽極由于具有高的催化活性、高的析氧過電位和化學(xué)惰性而受到關(guān)注。電沉積二氧化鉛時(shí)，添加某些外來離子或顆粒能改善其電催化活性和穩(wěn)定性，這些離子和顆粒主要包括Bi3+、F−、Fe3+、Co2+、Ce3+、Ru3+、As3+、Co3O4、RuO2、PbO2、A12O3和TiO2等。闡述了二氧化鉛的應(yīng)用領(lǐng)域，討論了電沉積摻雜二氧化鉛的制備方法及其影響因素；針對二氧化鉛固有的催化活性和脆性的缺陷，評述了摻雜離子和固體顆粒的二氧化鉛鍍層的優(yōu)缺點(diǎn)。結(jié)果表明：摻雜Bi3+、F−、Ce3+、Ru3+和Ag+離子能提高二氧化鉛的催化活性；摻雜In3+、PO43-和As3+能抑制二氧化鉛的晶核形成；提出外來離子摻雜在二氧化鉛晶格缺陷中的幾種模式：可變價(jià)的金屬離子取代Pb4+，并且自身被氧化成高價(jià)的金屬離子摻雜在二氧化鉛鍍層中，這些金屬離子是Bi3+、Ce3+、Ru3+、Ag+、Co2+和As3+；在F修飾的二氧化鉛中，F(xiàn)−離子替代兩個(gè)OH−離子；Fe3+分別在低溫和高溫下取代Pb2+和Pb4+；F−離子分別與Fe3+或Co2+形成協(xié)同效應(yīng)。復(fù)合鍍層的電催化作用與摻雜的催化粒子類型及其應(yīng)用領(lǐng)域有關(guān)，例如：PbO2+RuO2復(fù)合鍍層在硫酸溶液中顯示最好的催化活性；PbO2+Co3O4在氫氧化鈉溶液中具有最好的電催化活性；當(dāng)然，復(fù)合鍍層的表面粗糙度的影響不能完全忽視。摻雜PTFE和TiO2顆粒能顯著的降低二氧化鉛鍍層的脆性。展望了摻雜二氧化鉛鍍層的發(fā)展趨勢。
關(guān)鍵字: 二氧化鉛；電沉積；摻雜離子；摻雜顆粒；催化活性；脆性
（Faculty of Materials and Metallurgical Engineering, Kunming University of Science and Technology, Kunming 650093, China）
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(xiàn)−+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.
Key words: PbO2; electrodeposition; doping-ions; doping-particles; catalytic activity; brittleness
