Electrosynthesis and Physicochemical Properties of PbO2 Films
Electrosynthesis and Physicochemical Properties of PbO2 Films
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DOI：
10.1149/1.1495498
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发表时间：
2002-09
影响因子：
3.9
通讯作者：
A. Velichenko;R. Amadelli;A. Benedetti;D. Girenko;S. Kovalyov;F. Danilov
中科院分区：
文献类型：
--
作者：
A. Velichenko;R. Amadelli;A. Benedetti;D. Girenko;S. Kovalyov;F. Danilov
用电化学和X射线衍射方法研究了硝酸溶液中二氧化铅在铂表面沉积过程中电位和温度的变化。结果表明，这些参数强烈影响的PhO 2薄膜的形貌和电催化活性。电沉积过程符合电化学、化学、电化学机理：（i）H2 O → OHads + H + + e，（ii）Ph 2+ + OHads → Pb（OH）2+，（iii）Pb（OH）2+ + H2 O → PbO 2 + 3 H + + e，（iv）PbO 2 + 3 H + e，（v）PbO 2 + 3 H + e，（v）PbO 2 + 3 H +3 H + e。第二电子转移阶段和Pb 2+扩散分别在较低和较高的过电位范围内控制二氧化物的形成。温度和电位（或电流）是电沉积过程中的重要参数。取决于电势区域，该过程可以是动力学或扩散控制的。在酸性电解液中，主要是β PbO 2的电沉积，在动力学控制区，α相杂质的量随电位的增加而增加，在扩散控制区，α相杂质的量随电位的增加而减少。此外，相对较低的电沉积电位和较高的温度有利于α-和β-PbO 2改性的微晶尺寸的增加和择优晶体取向。生长溶液的温度影响所得氧化物沉积物的结晶度，并且对它们在高正电位下的工艺（例如臭氧生成）中作为阳极的性能具有显著影响。
An electrochemical and X-ray diffraction study has been conducted on the formation of lead dioxide deposits on platinum, from nitric acid solutions, as a function of potential and temperature. It has been shown that these parameters strongly influence the morphology and electrocatalytic activity of the PhO 2 films. The electrodeposition process is satisfactorily described by an electrochemical, chemical, electrochemical mechanism: (i) H 2 O → OH ads + H + + e; (ii) Ph 2+ + OH ads → Pb(OH) 2+ ; (iii) Pb(OH) 2+ + H 2 O → PbO 2 + 3H + + e; the second electron transfer stage and Pb 2+ diffusion control the dioxide formation in the lower and higher overpotential range, respectively. Temperature and potential (or current) are important parameters in the electrodeposition process. Depending on the potential region, the process can he kinetically or diffusion controlled. In an acid electrolyte, where mainly the β-PbO 2 modification is electrodeposited, the amount of α-phase impurity increases with increasing potential in the kinetically controlled region and decreases in the diffusion controlled domain. In addition, relatively low electrodeposition potentials and high temperatures favor an increase of the crystallite size with preferred crystallographic orientation for both α- and β-PbO 2 modifications. The temperature of the growth solution affects the crystallinity of the resulting oxide deposits and has a marked effect on their performance as anodes in processes at high positive potentials such as ozone generation.