铅锡合金在硫酸溶液中生长阳极Pb(Ⅱ)氧化物膜的机理

The Growth Mechanism of the Anodic Pb(Ⅱ) Film Formed on Lead-tin Alloy in Sulfuric Acid Solution

用交流阻抗、开路电位衰退及线性电位扫描等方法在 0 .9V( vs.Hg/Hg2 SO4)和 4 .5 mol/L H2 SO4溶液中 ,研究了铅及 Pb-Sn合金电极上所生长的阳极氧化物膜 .实验结果表明 ,阳极膜由溶解 -沉淀机理控制生长 ,膜中微粒间为液膜 ,借助液膜作为离子通道可使膜中微粒发生阳极反应 ,锡有利于膜中 Pb O微粒表层阳极氧化为 Pb O1 + x( 0 <x<1 )

The properties of the anodic oxide film formed on Pb and Pb Sn alloy in 4.5 mol/L H 2SO 4 solution at 0.9 V( vs . Hg/Hg 2SO 4) have been investigated by the a.c. technique, open circuit decay curve, and linear sweep voltammetry. It was found that the anodic film grows via a dissolution precipitation process. The PbO particles in the anodic film may be anodized further by using the interstitial liquid among the PbO particles for ionic transportation. Tin facilitates the process of oxidation of the surface layer of the PbO particles to PbO 1+x (0<x <1).