Pore-size control dynamics of nanoporous metals based on in-situ observations and atomic simulation

在高温下对纳米多孔金进行了原位透射电子显微镜观察。即使在相同的样品中，通过溅射Au-Ag和随后的去合金化制备的样品也会出现不均匀的粗化。因此，由于这种不均匀，很难估计粗化行为。作为纳米多孔金属比表面积的探针，考察了纳米多孔金对有机染料脱色的催化性能。甲基橙的分解反应动力学常数与循环伏安法估算的比表面积不成正比。因此，纳米多孔金的韧带表面的原子缺陷是催化反应的特异点。用第一性原理方法模拟的Au(111)表面原子缺陷的电子结构也支持表面原子缺陷的作用。

In-situ transmission electron microscopic observations of nanoporous Au at high temperatures were conducted. Nonuniform coarsening occured even in an identical sample which had been fabricated by sputtering of Au-Ag and subsequent dealloying. Therefore it is suggested that the estimation of coarsening behavior is difficult because of this nonuniformness.As a probe for surface area of nanoporous metals, catalytic properties of nanoporous Au for decoloration of organic dyes were examined. The reaction kinetic constant for decomposition of methyl orange was not proportional to the surface area estimated by cyclic voltammetry. Therefore the atomic defects on ligament surface of nanoporous Au serve as specific points for the catalytic reaction. The role of surface atomic defects is also supported by the electronic structure by atomic defects on the Au (111) surface simulated by first-principles calculations.