Display options
Cite
Duinea MI, Costas A, Baibarac M, et al. Mechanism of the cathodic process coupled to the oxidation of iron monosulfide by dissolved oxygen. J Colloid Interface Sci. 2016;467:51-59doi: 10.1016/j.jcis.2016.01.010.
Duinea, M. I., Costas, A., Baibarac, M., & Chiriță, P. (2016). Mechanism of the cathodic process coupled to the oxidation of iron monosulfide by dissolved oxygen. Journal of colloid and interface science, 46751-59. https://doi.org/10.1016/j.jcis.2016.01.010
Duinea, Mădălina I, et al. "Mechanism of the cathodic process coupled to the oxidation of iron monosulfide by dissolved oxygen." Journal of colloid and interface science vol. 467 (2016): 51-59. doi: https://doi.org/10.1016/j.jcis.2016.01.010
Duinea MI, Costas A, Baibarac M, Chiriță P. Mechanism of the cathodic process coupled to the oxidation of iron monosulfide by dissolved oxygen. J Colloid Interface Sci. 2016 Apr 01;467:51-59. doi: 10.1016/j.jcis.2016.01.010. Epub 2016 Jan 06. PMID: 26773612.
Copy Download .nbib Format: NLM
Share it on

J Colloid Interface Sci. 2016 Apr 01;467:51-59. doi: 10.1016/j.jcis.2016.01.010. Epub 2016 Jan 06.

Mechanism of the cathodic process coupled to the oxidation of iron monosulfide by dissolved oxygen.

Journal of colloid and interface science

Mădălina I Duinea, Andreea Costas, Mihaela Baibarac, Paul Chiriță

Affiliations

  1. University of Craiova, Department of Chemistry, Calea Bucuresti 107I, Craiova 200478, Romania.
  2. National Institute of Materials Physics, Laboratory of Optical Processes in Nanostructured Materials, P.O. Box MG-7, Bucharest R077125, Romania.
  3. University of Craiova, Department of Chemistry, Calea Bucuresti 107I, Craiova 200478, Romania. Electronic address: [email protected].

PMID: 26773612 DOI: 10.1016/j.jcis.2016.01.010

Abstract

This study investigated the mechanism of iron monosulfide (FeS) oxidation by dissolved oxygen (O2(aq)). Synthetic FeS was reacted with O2(aq) for 6days and at 25°C. We have characterized the initial and reacted FeS surface using Scanning Electron Microscopy coupled with Energy Dispersive X-ray (SEM/EDX) analysis, Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). It was found that during the aqueous oxidation of FeS new solid phases (disulfide, polysulfide, elemental sulfur, ferric oxyhydroxides and Fe3O4) develop on the mineral surface. The results of potentiodynamic polarization experiments show that after 2days of FeS electrode immersion in oxygen bearing solution (OBS) at initial pH 5.1 and 25°C the modulus of cathodic Tafel slopes dramatically decreases, from 393mV/dec to 86mV/dec. This decrease is ascribed to the change of the mechanism of electron transfer from cathodic sites to O2 (mechanism of cathodic process). The oxidation current densities (jox) indicate that mineral oxidative dissolution is not inhibited by pH increase up to 6.7. Another conclusion, which emerges from the analysis of jox, is that the dissolved Fe(3+) does not intermediate the aqueous oxidation of FeS. The results of electrochemical impedance spectroscopy (EIS) show that after 2days of contact between electrode and OBS the properties of FeS/water interface change. From the analysis of the EIS, FTIR spectroscopy, Raman spectroscopy and SEM/EDX data we can conclude that the change of FeS/water interface properties accompanies the formation of new solid phases on the mineral surface. The new characteristics of the surface layer and FeS/water interface do not cause the inhibition of mineral oxidation.

Copyright © 2016 Elsevier Inc. All rights reserved.

Keywords: EIS; FeS oxidation; FeS/water interface; Raman spectroscopy; SEM/EDX

Publication Types