锌钴异常共沉积机理研究
来源期刊：中南大学学报(自然科学版)1993年第5期
论文作者：黄振谦 胡国荣
文章页码：689 - 694
关键词：锌; 钴; 氢氧化锌; 电沉积; 吸附; pH值; 抑制; 异常共沉积
Key words：zinc; cobalt; zinc hydroxide; electrodeposition; adsorption; inhibition; abnormal codeposition
摘 要：用电化学方法研究了锌钴异常共沉积机理。实验结果表明,单独电沉积时,在不同电极上,钴离子的沉积电位都比锌离子正100mV至200mV;当锌钴共沉积时,钴受到抑制,其沉积电位变得比锌更负。用锑微电极跟踪电极表面附近pH值发现,钴沉积时,电极表面附近pH值升高。同时,Zn2+生成Zn(OH)2,并吸附在电极表面上,阻碍CO2+的进一步放电。据此阐明了锌钴异常共沉积机理。
Abstract: Mechanism of abnormal codeposition of zinc and cobalt is studied by various methods ofelectrochemistry.The results show that the deposition potential of cobalt is always 100 mv to 200 mv more positive than that of zinc when they are deposited separately on varied electrodes.Nev-ertheless,the deposition of cobalt is subjected to inhibition and deposition potential is even more negative than zinc when they are codeposited.It is found by measurement of pH with a micro-electrode of antimony that pH near electrode surface increases and Zn2+ turns to Zn(OH)2 adsorbed on electrode surface,which will suppress electrodeposition of cobalt,as cobalt is deposited.Adsorption of Zn(OH)2 on the electrode surface is verified in our experiment.A proposed mechanism of abnormal codeposition of zinc and cobalt is concluded finally.
