Refinement of Nanoporous Copper by Dealloying MgCuY Amorphous Alloys in Sulfuric Acids Containing Polyvinylpyrrolidone
Refinement of Nanoporous Copper by Dealloying MgCuY Amorphous Alloys in Sulfuric Acids Containing Polyvinylpyrrolidone
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DOI：
10.1149/2.076403jes
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发表时间：
2014-01-01
影响因子：
3.9
通讯作者：
Hara, Nobuyoshi
中科院分区：
文献类型：
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作者：
Dan, Zhenhua;Qin, Fengxiang;Hara, Nobuyoshi
在聚乙烯吡咯烷酮(PVP)和硫酸的混合溶液中，用脱合金化的方法制备了纳米多孔铜。与不含PVP的0.1M H_2SO_4溶液相比，在混合溶液中脱合金时，孔洞和韧带的大小发生了显著变化：在含有10g/L PVP的混合溶液中，孔和韧带的平均尺寸分别为10 nm和14 nm，而在不含PVP的混合溶液中，孔和韧带的平均尺寸分别为66 nm和84 nm。随着脱合金液中PVP浓度的增加，纳米孔和韧带的尺寸减小：PVP浓度在0~0.1g/L范围内减小较小(类型I)，而在0.1~10g/L范围内减小较大(类型II)。加入10g/L PVP后，表面扩散系数降低了三个数量级以上。这可能是由于PVP大分子的吸附限制了铜原子的自由扩散，迫使铜原子在相对较窄的范围内扩散，从而形成了较小的铜韧带和纳米孔。在脱合金液中引入有机大分子有助于细化纳米孔结构。(C)2014年电化学会。版权所有。
Nanoporous Cu was fabricated by dealloying Mg65Cu25Y10 amorphous alloy in a mixed solution of poly-vinylpyrrolidone (PVP) and sulfuric acid. A significant change was observed in the pore and ligament size when dealloying in the mixed solution rather than in a 0.1 M H2SO4 solution free of PVP: in the mixed solution containing 10 g/L PVP the mean sizes of pores and ligaments were 10 nm and 14 nm, whereas they were 66 nm and 84 nm in the PVP-free solution. With increasing concentration of PVP in the dealloying solutions, the size of nanopores and ligaments decreased in the following manner: the decrease was small in the PVP concentration range of 0 to 0.1 g/L (Type I), and large in the 0.1 to 10 g/L range (Type II). A decrease in the surface diffusivity of more than three orders of magnitude was noted with the addition of 10 g/L PVP. This can be explained by the restrictions on free diffusion of Cu adatoms due to the adsorption of PVP macromolecules which force Cu adatoms to diffuse in a relatively narrower range, and thus smaller Cu ligaments and nanopores formed. The introduction of organic macromolecule into dealloying solution helps refine nanoporous structures. (C) 2014 The Electrochemical Society. All rights reserved.