金在微电极上的电沉积研究

Gold Electrodeposition on Microelectrodes

本工作利用循环伏安法和阶跃电位法研究在ＡｕＣｌ３的酸性溶液中金在玻碳和铂微电极上的电沉积行为．结果表明，金在微电极上成核所需的过电位较高，但成核几率也高，在所研究的微电极尺寸范围内，金可形成大量的临界单核，且核的生长速率很快．铂微电极上金电沉积的Ⅰ－ｔ曲线符合连续成核的模式．玻碳微电极的沉积历史对金的电沉积行为的影响较大，可以加速金的成核和生长，而铂却没有这种影响．

The initial stage electrodeposition behaviors of gold onto glassy carbon and platinum microelectrodes are studied in an acid solution containing AuCl_3using cyclic voltammetry and potential step techniques. The results suggest that gold nucleation on microelectrodes requires a higher driving force with high probability. Within the range of the microelectrode dimension that have been used in the present work, large amount of gold nucleus could be formed at short time scale at overpotentials higher than a threshole value. The It curves from the platinum microelectrode are in consistence with the continuous nucleation model. It has been found that the deosition history of the glassy carbon microelectrode substrate has strong influences on subsequent electrodeposition behavior while the platinum microelectrode does not show such effects.