Effects of sulfurous acid on anodic process of gold electrode in thiourea solution
来源期刊：中南大学学报(英文版)2003年第2期
论文作者：龙怀中 舒万艮
文章页码：126 - 129
Key words：thiourea;gold;electrochemistry
Abstract: The electrochemistry behaviors of gold electrode in thiourea solution were studied by using electrochemical techniques, such as potentiodynamic, voltammogram and current step. A catalytical electrochemical-reduction mechanism was proposed to identify the anodic oxidation of gold in the thiourea solution. The results indicate that the decomposition of thiourea occurs when the electrode potential is higher than 640 mV. The addition of sulfurous acid presents a very posi- tive effect on the anodic process of gold electrode.The anodic oxidation rate of gold is 5 times faster than that without sulfurous acid.The passivity of gold electrode is attributed to the accumulation of elemental sulfur on the surface of gold.The sulfurous acid reacts with the oxidation product ((SC(NH)NH2)2) of thiourea,which can decrease the decomposition of thiourea and improves its stability.
