Tetren对锌电沉积过程的阻化作用和催化作用

应用线性扫描伏安法和微分电容法研究了锌酸盐镀锌中四乙烯五胺(tetren)对Zn(OH)₄^2-放电步骤的阻化和催化作用.结果表明,tetren在汞电极/溶液界面上具有较强的吸附性,且随着te-tren浓度提高吸附量增加,吸附电势区朝负电势方向扩大,tetren在-1.3～1.45V间可阻化Zn(OH)₄^2-放电.在小于-1.45V电势区可观察到两个催化电流峰,提高tetren浓度,两峰重合,其峰电流与tetren(大于5×10^-3mol/L时)及ZnO浓度成正比,而与NaOH浓度成反比.

Studies on the Inhibition and Catalysis Effects of Tetren in Zinc Electrodeposition

The inhibition and catalysis effects of tetren on discharge of Zn(OH)₄^2- in alkaline zincate bath have been studied by means of voltammetry and differential capacity measurement.The results show that tetren has a higher adsorptivity on Hg-electrode/solution interface.The adsorption quantity is increased and the potential range of adsorption is extended toward more negative potential with increasing of tetren concentration.It is found that tetren inhibits the discharge of Zn(OH)₄^2- at potentialbetween -1.3--1.45 V.At the potential more negative than - 1.45 V, two catalytic currentpeaks are observed on voltammetric curves, and they are merged into a peak as the concentration of tetren increased.As tetren concentration is higher than₅× 10^-3 mol/L, the peak current is directly proportional to the concentration of tetren and ZnOboth, but inversely proportional to NaOHconcentration.The relevant empirical formula are given in this paper, and the catalysis effect of tetren on Zn(OH)₄^2- dischage is discussed by homogeneous parallel reaction and the ion pairing effect.