Generalized Fabrication of Nanoporous Metals (Au, Pd, Pt, Ag, and Cu) through Chemical Dealloying
Generalized Fabrication of Nanoporous Metals (Au, Pd, Pt, Ag, and Cu) through Chemical Dealloying
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通过化学脱合金普遍制备纳米多孔金属（Au、Pd、Pt、Ag 和 Cu）
DOI：
10.1021/jp811445a
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发表时间：
2009-07-23
影响因子：
3.7
通讯作者：
Frenzel, Jan
中科院分区：
文献类型：
--
作者：
Zhang, Zhonghua;Wang, Yan;Frenzel, Jan
通过在自由腐蚀条件下对快速凝固的铝基合金进行化学去合金化，可以制备包括Au、Pd、Pt、Ag和Cu的纳米多孔金属带。这些纳米多孔金属的形成和微观结构已被研究，使用X射线衍射，扫描电子显微镜，能量色散X射线分析，透射电子显微镜，和高分辨率透射电子显微镜。所有的金属带都具有开放的三维双连续互穿的纳米尺度的韧带通道结构。对于给定的去合金化溶液，这些纳米多孔金属中的韧带/通道的长度尺度与更贵原子的表面扩散相关，并且随着扩散系数的增加而依次增加：Pt/Pd < Au < Ag < Cu。此外，这些纳米多孔金属的韧带/通道的长度尺度可以通过简单地改变去合金化溶液来调制。纳米压痕测试表明，纳米多孔金的杨氏模量和硬度取决于韧带/通道的长度尺度。这些纳米多孔金属的电阻率比其本体对应物的电阻率高一到两个数量级。这些纳米多孔金属可以是很好的候选人，以探测与纳米多孔固体的随机多孔结构相关的机械，物理和化学性质，并将在催化，传感器，致动器，燃料电池等方面找到广泛的应用。
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.