Sign-inverted surface stress-charge response in nanoporous gold
Sign-inverted surface stress-charge response in nanoporous gold
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DOI：
10.1016/j.susc.2008.09.038
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发表时间：
2008-12-01
期刊：
影响因子：
1.9
通讯作者：
Weissmueller, Joerg
中科院分区：
文献类型：
--
作者：
Jin, Hai-Jun;Parida, Smrutiranjan;Weissmueller, Joerg
表面应力-电荷系数zeta量化了表面应力-固体表面的基本性质-对表面电荷的添加或去除的响应。到目前为止，所有的实验都发现zeta在干净的金属表面是负的。在这里，我们报告在原位纳米多孔金样品的脱合金化实验。结果表明，在循环电位扫描的阳极部分期间，大的可逆弹性收缩。该行为表明zeta的异常正信号，可以与在去合金化期间形成的强烈吸附氧的单层以及当氧化物就位时材料的非常小（1- 2nm）的结构尺度相关联。在阴极还原之后，zeta回复到清洁金属表面的传统负号。我们讨论了在金属和氧化物覆盖的表面的电子屏蔽有关的zeta符号。(C)2008 Elsevier B. V.保留所有权利。
The surface stress-charge coefficient, zeta, quantifies the response of the surface stress - a fundamental property of solid surfaces - to the addition or removal of superficial electric charge. So far, all experiments have found zeta negative at clean metal surfaces. Here we report in situ dilatometry experiments on nanoporous gold samples prepared by dealloying. The results reveal a large reversible elastic contraction during the anodic part of cyclic potential scans. The behavior, which indicates an abnormal positive sign of zeta, can be linked to a monolayer of strongly adsorbed oxygen formed during dealloying, and to the extraordinarily small (1-2 nm) structure scale of the material while the oxide is in place. After cathodic reduction, zeta reverts to the conventional, negative sign of the clean metal surface. We discuss the sign of zeta in relation to the electronic screening at metallic and oxide-covered surfaces. (C) 2008 Elsevier B.V. All rights reserved.