Electrochemical formation of green rusts in deaerated seawater-like solutions
Electrochemical formation of green rusts in deaerated seawater-like solutions
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DOI：
10.1016/j.electacta.2011.04.123
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发表时间：
2011-07
影响因子：
6.6
通讯作者：
P. Refait;D. Nguyen;M. Jeannin;S. Sablé;M. Langumier;R. Sabot
中科院分区：
文献类型：
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作者：
P. Refait;D. Nguyen;M. Jeannin;S. Sablé;M. Langumier;R. Sabot
碳钢电极在脱气的海水样电解质（0.5 mol dm-3 NaCl，0.03 mol dm-3 Na 2SO 4，0.003 mol dm-3 NaHCO 3）中，在比开路电位高150 mV的电位下极化。X射线衍射和μ-拉曼分析表明，钢表面生长了一层主要由GR（SO 42-）组成的层。GR（SO 42-）伴随着GR（CO 32-）的痕迹。在由0.3 mol dm-3的Na 2SO 4和0.03 mol dm-3的NaHCO 3组成的溶液中进行的类似实验得到了相同的结果。因此，在钢上形成的GR的性质主要与硫酸盐与碳酸盐的浓度比有关。最后，将在La罗谢尔港（大西洋海岸）浸泡11年的碳钢试样从海水中取出进行分析。锈层的内部被证明主要由磁铁矿、GR（SO 42 −）和硫化铁FeS组成。这明确地证实了GR（SO 42 −），如Fe 3 O 4和FeS，可以在贫氧环境中从钢中形成。
Carbon steel electrodes were polarised at a potential ∼150 mV higher than the open circuit potential, in a deaerated seawater-like electrolyte (0.5 mol dm−3NaCl, 0.03 mol dm−3Na2SO4, 0.003 mol dm−3NaHCO3). X-ray diffraction and μ-Raman analysis demonstrated that a layer mainly composed of GR(SO42−) had grown on the steel surface. GR(SO42−) was accompanied by traces of GR(CO32−). Similar experiments performed in a solution composed of 0.3 mol dm−3of Na2SO4and 0.03 mol dm−3of NaHCO3led to the same result. The nature of the GR forming on steel is thus mainly linked to the sulphate to carbonate concentration ratio. Finally, carbon steel coupons immersed for 11 years in the harbour of La Rochelle (Atlantic coast) were removed from seawater for analysis. The inner part of the rust layer proved to be mainly composed of magnetite, GR(SO42−) and iron sulphide FeS. This definitively confirms that GR(SO42−), as Fe3O4and FeS, can form from steel in O2-depleted environments.