UMR-CNRS 6503, University of Poitiers, 40 Avenue du Recteur Pineau, 86022 Poitiers Cedex, France.
J Synchrotron Radiat. 2010 Jan;17(1):81-5. doi: 10.1107/S0909049509040680. Epub 2009 Nov 14.
This work demonstrates the utility of synchrotron infrared reflectance microspectroscopy in the far- and mid-IR for the determination of the composition of electrogenerated surface films formed during the general and localized corrosion of copper in alkaline and bicarbonate solutions. Back-reflection geometry has been employed to identify the anodic film formed on copper in 0.1 M NaOH solution at 0.3 V (versus a Ag/AgCl reference) to be mainly CuO. In 0.01 M NaHCO(3) solution general corrosion occurs with passive film formation below 0.2 V. The surface film at 0.2 V consisted mainly of bicarbonate, copper carbonate dihydroxide or malachite [CuCO(3).Cu(OH)(2)], Cu(OH)(2) and possibly some CuO. At higher potentials the passive film breaks down and localized corrosion occurs leading to the formation of pits. The composition of the surface films inside the pits formed at 0.6 V was found to be essentially the same as that outside but the relative amount of Cu(OH)(2) appears to be higher.
这项工作展示了同步辐射红外反射光谱在远-中和中红外区用于确定铜在碱性和碳酸氢盐溶液中普遍和局部腐蚀过程中形成的电生成表面膜的组成的实用性。采用背反射几何形状，在 0.3 V（相对于 Ag/AgCl 参比电极）下确定了在 0.1 M NaOH 溶液中形成的铜的阳极膜，主要为 CuO。在 0.01 M NaHCO3 溶液中，普遍腐蚀发生在低于 0.2 V 的钝化膜形成过程中。在 0.2 V 时的表面膜主要由碳酸氢盐、碳酸铜二羟基或孔雀石[CuCO3.Cu(OH)2]、Cu(OH)2 和可能的一些 CuO 组成。在较高的电位下，钝化膜破裂，局部腐蚀发生，导致点蚀的形成。在 0.6 V 形成的点蚀内部的表面膜的组成基本上与外部相同，但 Cu(OH)2 的相对含量似乎更高。
