Study on Mechanisms on Metal Surface in Aqueous Solution by Electrochemical QCM Technique

用电化学石英晶体微天平技术研究了金属电极表面的反应机理。研究结果包括以下四个部分。(1)在pH 1的KOH溶液中，用循环伏安法测定了由镍锌合金浸锌制备的多孔镍电极和标准镍电极的质量变化。两种电极的电位和电流值不同，但CV曲线形状相似。随着循环次数的增加，两种电极上的质量增加。但多孔镍电极中存在一个质量增加-质量损失区，这是镍电极中所没有的。这一行为将使多孔镍电极比镍电极具有更高的活性表面。(2)用电沉积法研究了在酸性硫酸盐体系中形成CuInX_2（X=Se，Te）半导体化合物过程中硫属元素的还原行为。Se和Te的还原行为以相似的机理进行，但Se和Te的还原速率随温度的升高而增大。 ...更多信息 反应电位不同。X单质在0价态还原沉积后，继续还原至-2价态，沉积物溶解。在CuInX_2（X=Se，Te）化合物电沉积过程中，沉积Cu-X合金后，合金中的X以X^2-形式固溶。In^&lt;3+&gt;与X^反应生成In-X合金<2->，最后生成CuInX_2化合物。(3)研究了一种不采用氰化工艺的选择性浸金新方法--加钛碱液选择性浸金法。结果表明，添加亚硫酸后，浸出率提高。存在选择性溶解金的有效电位，过高的阳极电位会使硫脲氧化。(4)采用EQCM技术研究了Zn 2+和PO 4+<3->体系作为阴极缓蚀剂在金属表面的吸附和成膜行为。通过EQCM测量质量变化计算的膜厚度为几十nm，并且通过AFM观察其均匀地形成在表面上。在阴极极化条件下，缓蚀剂的吸附成膜有两种情况，一种是逐渐成膜，另一种是快速成膜。少

Reaction mechanisms on the surface of metal electrode were investigated by electrochemical quarts crystal microbalance, EQCM,technique. The results consists of four parts as follows.(1) The mass changes of Ni porous electrode prepared from Zn leaching of Ni-Zn alloy and standard Ni electrode were measured during cyclic voltammetry in pH 1 KOH solution. The values in potential and in current were different for both electrodes, but the shape of CV carve was similar. Mass gain was found on both electrodes with the increase of cycle number. Though, in porous Ni electrode, there was a mass gain-mass loss area in potential, that wasn't found in Ni electrode. This behavior would give the more active surface to the porous Ni electrode than Ni one.(2) Reduction behavior of chalcogen in the formation of CuInX_2 (X=Se, Te) semiconductor compounds from acidic sulfate bath was investigated by electrodeposition method. Reduction behaviors of Se and Te proceeded in the similar mechanism, though the r … More eaction potential was different. After the reduction deposition in 0 valency as X simple element, X was continuously reduced until -2 valency, and following to the dissolution of deposits. During the electrodeposition of CuInX_2 (X=Se, Te) compound, X in alloy solved out as X^2-after Cu-X alloy deposited. In-X alloy formed after In^<3+> reacted with X^<2->, and finally, CuInX_2 compounds formed.(3) As a new leaching method of the gold without using cyanidation process, the selective gold leaching method was investigated using the alkali solution with tiourea. As a result, it was found that leaching ability improved by adding sulfurous acid by EQCM technique. The effective potential existed to dissolve gold selectively and thiourea was oxidized when anode potential was too high.(4) The adsorption and film formation behaviors of Zn^<2+> and PO_4^<3-> system as cathode inhibitor onto the metal surface was investigated to protect metals from corrosion by EQCM technique. The film thickness was dozens of nm from calculation of mass change by EQCM measurement, and it formed uniformly on the surface from AFM observation. There were two cases in adsorption and film formatin by the corrosion inhibitor under the cathodic polarization condition, one was gradual formation and the other was rapid formation. Less