| Title | Electrochemical investigation of the oxidation of pyrite in neutral solutions |
| Authors | Liu, Tong Hu, Yutian Chen, Nan Xue, Lijing Feng, Chuanping Ye, Yubo |
| Affiliation | China Univ Geosci Beijing, Sch Water Resources & Environm, MOE Key Lab Groundwater Circulat & Environm Evolu, Beijing 100083, Peoples R China Peking Univ, Sch Earth & Space Sci, Key Lab Orogen Belts & Crustal Evolut, Beijing 100080, Peoples R China |
| Keywords | IMPEDANCE SPECTROSCOPY ANODIC-DISSOLUTION SURFACE OXIDATION FES2 IRON OXYGEN |
| Issue Date | 10-Oct-2021 |
| Publisher | ELECTROCHIMICA ACTA |
| Abstract | Pyrite, as the most common sulfide on the Earth's surface, is of central importance in a devastating en-vironmental issue known as acid mine drainage (AMD). Although the oxidation of pyrite under neutral conditions is related to numerous environmental issues and industrial processes, its puzzling chemistry is largely unknown. Here, we analyzed the behavior and mechanism of pyrite oxidation in neutral solu-tions using a combination of electrochemical techniques. The oxidation of pyrite under neutral conditions followed a two-step oxidation law, i.e., below 0.4 V oxidation of iron occurred mainly, and oxidation of sulfur occurred above 0.4 V. Below 0.7 V, a typical passivation behavior of pyrite oxidation existed and can be eliminated with anodic potential higher than 0.7 V. In situ Fourier-transformed electrochemical impedance spectroscopy showed that the surface layer formed during oxidation in neutral conditions was mainly from iron oxidation products rather than sulfur oxidation products. These results indicated that the passivation of pyrite does not originate from the surface sulfur film, but should be explained by the semiconductor properties of pyrite. (c) 2021 Elsevier Ltd. All rights reserved. |
| URI | http://hdl.handle.net/20.500.11897/624217 |
| ISSN | 0013-4686 |
| DOI | 10.1016/j.electacta.2021.139078 |
| Indexed | SCI(E) |
| Appears in Collections: | 地球与空间科学学院 造山带与地壳演化教育部重点实验室 |
