Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (MOE), School of Materials Science and Engineering, Shandong University, Jingshi Road 73, Jinan 250061, PR China.
Phys Chem Chem Phys. 2010 Feb 21;12(7):1453-72. doi: 10.1039/b919313h. Epub 2009 Dec 18.
The electrochemical dealloying of rapidly solidified Al-based alloys in a 1 M NaCl aqueous solution has been investigated using electrochemical measurements in combination with microstructural analysis. The results show that nanoporous metals (Au, Ag, Pd and Cu) with various morphologies can be fabricated through electrochemical dealloying of the Al-based alloys in the NaCl solution. The electrochemical behaviors of elemental metals (Al, Au, Ag, Pd and Cu) and precursor alloys for dealloying have been studied through open-circuit measurements, potentiodynamic anodic polarization and cyclic voltammetry. The dealloying mechanisms of the precursor alloys and the formation of the nanoporous metals have been analyzed based on cyclic voltammetry curves, chronoamperometry curves obtained at potentials above or below the critical potentials, and microstructural features of the as-dealloyed samples. In addition, a classification for dealloying of a bi-phasic alloy has been proposed according to different dealloying behaviors of coexistent phases in the alloy. It has been found that interactions between coexistent phases prevail during dealloying of the bi-phasic alloy and are in principle dependent on the diffusivity of the more noble element, the curvature-dependent undercritical potential dissolution, and the reaction between the more noble element and chloride ion.
采用电化学测试与微观结构分析相结合的方法，研究了在 1 M NaCl 水溶液中快速凝固 Al 基合金的电化学脱合金化。结果表明，通过在 NaCl 溶液中电化学脱合金化，可以制备出具有各种形貌的纳米多孔金属（Au、Ag、Pd 和 Cu）。通过开路测量、动电位阳极极化和循环伏安法研究了元素金属（Al、Au、Ag、Pd 和 Cu）和脱合金用前驱体合金的电化学行为。基于循环伏安曲线、高于或低于临界电位时获得的计时电流曲线以及样品的微观结构特征，分析了前驱体合金的脱合金机制和纳米多孔金属的形成。此外，根据合金中共存相的不同脱合金行为，提出了双相合金脱合金的分类。研究发现，在双相合金的脱合金过程中，共存相之间的相互作用占主导地位，这主要取决于更贵金属的扩散率、亚临界电位下的曲率依赖性溶解以及更贵金属与氯离子之间的反应。
