摘要
Anodic behavior of pure Au as compared to platinum （Pt） in H2SO4 solutions was considered by different electrochemical techniques for an appropriate insight. Cyclic voltammetry studies showed two oxidation and one film reduction peaks for Au, while one oxygen evolution reaction for Pt. Increasing H2804 concentration （from 0.5 to 1 mol/L） caused 2-fold increases in peak current density of Au. Increase in agitation promoted passive zone of Au, while it was negligible for Pt by potentiodynamic studies. Potentiostatic studies （2 h） at three anodic passive potentials in 1 mol/L H2SO4 showed that the admittance of Au was found to be the lowest at 1.4 V. Electrochemical noise measurements during the decay periods （16 h） after polarization showed that the thin passive film formed during potentiostatic polarization has been dissolved.
采用不同电化学测试技术研究纯金和铂电极在硫酸溶液中的阳极行为。循环动电位法研究表明,金电极极化时会出现2个氧化峰和1个还原峰,而铂电极只有1个析氧反应峰出现。将硫酸浓度从0.5 mol/L增加到1mol/L时,金电极的峰电流密度增加2倍。动电位法研究表明,增加搅拌速度会提高金的钝化区域,而对铂电极无影响。2 h的恒电位法研究表明,在1mol/L硫酸溶液中,在3个不同的阳极电位极化下,1.4 V时金电极的腐蚀速率最低。电化学噪音技术测试研究表明,在16 h的电位衰退中,在恒电位极化时所形成的钝化膜已经溶解。
基金
Project(RDCPJ428402) supported by the Natural Sciences and Engineering Research Council of Canada,Barrick Gold Corporation,Hydro-Quebec,Zinc Electrolytic of Canada
