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

用电化学石英晶体微天平、EQCM技术研究了金属电极表面的反应机理。主要研究结果如下：(1)测定了镍锌合金锌浸出法制备的多孔镍电极和标准镍电极在pH为1的KOH溶液中循环伏安过程中的质量变化。两种电极的电位值和电流值不同，但CV曲线形状相似。随着循环次数的增加，两种电极均获得了质量增益。但在多孔镍电极中，存在着镍电极所没有的电势增质损失区。(2)用电沉积方法研究了硫化物在酸性硫酸盐溶液中生成CuInX_2(X=Se，Te)半导体化合物的还原行为。Se和Te的还原行为具有相似的机理，但r…更多的动作电位是不同的。在0价态还原沉积为X单元素后，X不断还原到-2价，随后沉积溶解。在电沉积CuInX_2(X=Se，Te)化合物的过程中，合金中的X在沉积后以X^2-的形式析出。In^&lt；3+&gt；后形成的In-X合金与X^&lt；2-&gt；反应生成CuInX_2化合物。(3)作为一种新的无氰化浸金方法，研究了硫脲碱性溶液选择性浸金的方法。结果表明，添加亚硫酸后，EQCM技术的浸出能力有所提高。阳极电位过高时，存在选择性溶解金的有效电位，硫脲被氧化。(4)采用EQCM技术研究了阴极缓蚀剂Zn~(2+)和PO_4~(2+)体系在金属表面的吸附成膜行为。EQCM测量计算出薄膜的质量变化为几十nm，原子力显微镜观察到薄膜在表面形成均匀。在阴极极化条件下，缓蚀剂的吸附成膜有两种情况，一种是逐渐形成的，一种是快速形成的。较少

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