Hierarchical porous gold electrodes: Preparation, characterization, and electrochemical behavior
Hierarchical porous gold electrodes: Preparation, characterization, and electrochemical behavior
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DOI：
10.1016/j.jelechem.2012.08.025
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发表时间：
2012-09-15
影响因子：
4.5
通讯作者：
Collinson, Maryanne M.
中科院分区：
文献类型：
--
作者：
Zhao, Bo;Collinson, Maryanne M.
具有明确双峰结构的分层多孔金薄膜是通过在覆盆子状乳胶球（1200/60 nm）的密堆积组件周围以恒定电流电沉积金，然后去除模板而制成的。当金达到 1/2 层或 11/2 层厚时，电沉积停止，从电位与时间轨迹的振荡可以明显看出。扫描电子显微镜 (SEM) 图像显示了分级孔隙结构，其中有一组类似于 20 nm 的小开口，位于类似于 1200 nm 直径的大孔中。在进行电化学表征之前，通过化学方法和/或通过紫外线辐射清洁电极，并使用 X 射线光电子能谱 (XPS) 来评估残留聚苯乙烯的存在。在调查的三种清洁方法中。事实证明，在氯仿-丙酮中超声处理，然后进行紫外线辐射效果最好。通过积分氧化金峰下的面积确定的分级多孔金电极的表面积比裸金电极大 4 倍，比使用单峰、直径 1200 nm 乳胶球作为模板制备的大孔金电极大 2 倍。使用循环伏安法测定电极相对于大孔金和扁平金的电化学性能。结果表明，非法拉第电流与电极面积成线性关系，而扩散电化学可逆氧化还原探针（二茂铁甲醇）的法拉第电流则不然。对于吸附的氧化还原对（二茂铁己硫醇），不同电极的伏安波形和表面覆盖度不同。 (C) 2012 Elsevier B.V. 保留所有权利。
Hierarchical porous gold films with a well-defined bimodal architecture have been made by electrodepositing gold at a constant current around a close-packed assembly of raspberry-like latex spheres (1200/60 nm) followed by template removal. Electrodeposition was stopped when the gold was either 1/2 layer or 11/2 layer thick as evident from oscillations in the potential vs time traces. Scanning electron microscopy (SEM) images show the hierarchical pore structure with an ensemble of small similar to 20 nm openings located in a large similar to 1200 nm diameter macropore. Prior to electrochemical characterization, the electrodes were cleaned either chemically and/or via UV radiation and X-ray photoelectron spectroscopy (XPS) was used to evaluate the presence of residual polystyrene. Of the three cleaning methods investigated. sonication in chloroform-acetone followed by UV radiation proved best. The surface area of the hierarchical porous gold electrodes, determined by integrating the area under the gold oxide peak, was 4x larger than a bare gold electrode and 2x larger than a macroporous gold electrode prepared using uni-modal, 1200 nm diameter latex spheres as the template. The electrochemical performance of the electrodes relative to the macroporous gold and flat gold was undertaken using cyclic voltammetry. The results show that the non-Faradaic current scales linearly with electrode area while the Faradaic current of a diffusing electrochemically reversible redox probe (ferrocene methanol) does not. For an adsorbed redox couple (ferrocene hexanethiol), the voltammetric wave shapes and surface coverage were different for the different electrodes. (C) 2012 Elsevier B.V. All rights reserved.