Using Electrochemical Impedance Spectroscopy to Investigate Gold Dissolution in Thiourea and Thiocyanate Acid Solutions
Gold dissolution in acidic solutions containing thiourea (Tu) and thiocyanate was studied using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). In the presence of Tu, but in the absence of thiocyanate, passivation of gold occurred due to thiourea adsorption. When the solution also contained thiocyanate, passivation was significantly alleviated and gold dissolution enhanced. EIS revealed only one capacitive loop at 0.3 and 0.4V vs. SCE. The combination of the lixiviants lowered the polarization resistance for gold dissolution. A molar SCN:Tu ratio of 5:1 produced the lowest polarization resistance.
X. Yang et al., "Using Electrochemical Impedance Spectroscopy to Investigate Gold Dissolution in Thiourea and Thiocyanate Acid Solutions," ECS Transactions, The Electrochemical Society (ECS), Jan 2010.
The definitive version is available at http://dx.doi.org/10.1149/1.3367915
Materials Science and Engineering
Keywords and Phrases
Electrochemical Synthesis and Engineering
Article - Conference proceedings
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