Generalized Fabrication of Nanoporous Metals (Au, Pd, Pt, Ag, and Cu) through Chemical Dealloying

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• 作者：Zhonghua Zhang ; Yan Wang ; Zhen Qi ; Wenhua Zhang ; Jingyu Qin ; Jan Frenzel
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：July 23, 2009
• 年：2009
• 卷：113
• 期：29
• 页码：12629-12636
• 全文大小：456K
• 年卷期：v.113,no.29(July 23, 2009)
• ISSN：1932-7455

文摘

Nanoporous metal ribbons including Au, Pd, Pt, Ag, and Cu can be fabricated through chemical dealloying of rapidly solidified Al-based alloys under free corrosion conditions. The formation and microstructure of these nanoporous metals have been investigated using X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, and high-resolution transmission electron microscopy. All metal ribbons exhibit an open, three-dimensional bicontinuous interpenetrating ligament-channel structure with nanometer length scales. For a given dealloying solution, the length scale of ligaments/channels in these nanoporous metals is associated with surface diffusion of more noble atoms, and increases with increasing diffusion coefficients in sequence: Pt/Pd < Au < Ag < Cu. In addition, the length scale of ligaments/channels of these nanoporous metals can be modulated by simply changing the dealloying solution. Nanoindentation tests show that Young’s modulus and hardness of nanoporous gold are dependent upon the length scale of ligaments/channels. The electrical resistivity of these nanoporous metals is one to two orders of magnitude higher than that of their bulk counterparts. These nanoporous metals can be good candidates to probe the mechanical, physical, and chemical properties associated with random porous structures of nanoporous solids and will find wide applications in catalysis, sensors, actuators, fuel cells, and so forth.