某些添加剂对镍在玻璃碳上电结晶的影响

用阶跃电位法研究了光亮镍Watts镀液中添加剂:糖精、丁炔二醇和香豆素,对镍在玻璃碳上沉积初始阶段的影响.结果表明,在不含添加剂的该电解液,镍电结晶的初始阶段按连续成核的三维生长机理进行;分别或同时含有糖精和丁炔二醇时,则按瞬时成核的三维生长机理进行.糖精或丁炔二醇促进成核过程而阻化晶核的生长,这两种添加剂同时存在时则对成核和三维生长都起促进作用;添加香豆素或者同时添加三种添加剂不改变成核和生长的方式,但香豆素对成核过程和晶核生长都起着促进作用,而三种添加剂混用则对成核和生长过程起着阻化作用.本文采用Fleischmann等人郝二建模型.

The Effects of Some Additives on the Electrocrystallization of Nickel onto Vitreous Carbon Electrode

The effects of some conventional additives (saccharin, 1,4-butynediol and coumarin) on the initial stages of the electrodeposition of nickel from Watts type electrolytes onto vitreous carbon electrode have been examined using step potential method. It has been found that, in the electrolytes without any additives, the electrocrystallization of nickel follows the mechanism of three-dimensional progressive nucleation and growth, whereas in electrolytes with saccharin and/or 1,4-butynediol. it follows the mechanism of three-dimensional instantaneous nucleation and growth. When saccharin or 1,4-butynediol exists alone, nucleation is accelerated while crystal growth is inhibited; when these two additives exist simultaneously, both nucleation and growth are accelerated. If the electrolytes contain coumarin or the three additives mentioned above, the model of the nucleation and growth will be the same as that in the absence of additives. Coumarin alone promotes the nucleation and crystal growth, while co-existence of the three additives inhibits the nucleation and crystal growth. the phenomena are discussed in terms of the two-rate model proposed by Fleischmann et al.