Electrochemical Quartz Crystal Microbalance Study of FeS Particles Attached to Au Surface

Electrochemical quartz crystal microbalance (EQCM) measurements were employed for studying of the redox processes of FeS microparticles immobilized on Au electrode surface in contact with aqueous solutions of NaCl, NaCl-NaHCO3, and NaCl-Na2S. The objective was to shed light on the complexity of the iron sulfide electrochemistry. For the sake of comparison electrochemical behavior of FeS suspension was also investigated on the paraffin-impregnated graphite (PIGE) and hanging mercury drop (HMDE) electrodes. In order to understand the complex nature of the redox transformations of FeS, Mohr-salt was dissolved in NaCl and NaCl-NaHCO3 solutions, respectively, and the deposition-dissolution processes occurring in the course of the reduction of Fe(II) and reoxidation of Fe(0) were also monitored.