Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore 117576.
ACS Nano. 2012 Aug 28;6(8):7397-405. doi: 10.1021/nn302590k. Epub 2012 Jul 24.
Here we report the synthesis of Pt/Ag bimetallic nanostructures with controlled number of void spaces via a tailored galvanic replacement reaction (GRR). Ag nanocubes (NCs) were employed as the template to react with Pt ions in the presence of HCl. The use of HCl in the GRR caused rapid precipitation of AgCl, which grew on the surface of Ag NCs and acted as a removable secondary template for the deposition of Pt. The number of nucleation sites for AgCl was tailored by controlling the amount of HCl added to the Ag NCs or by introducing PVP to the reaction. This strategy led to the formation of Pt/Ag hollow nanoboxes, dimers, multimers, or popcorn-shaped nanostructures consisting of one, two, or multiple hollow domains. Due to the presence of large void space and porous walls, these nanostructures exhibited high surface area and improved catalytic activity for methanol oxidation reaction.
在这里，我们通过定制的电置换反应 (GRR) 报告了具有受控数量空隙的 Pt/Ag 双金属纳米结构的合成。Ag 纳米立方体 (NCs) 被用作模板，在存在 HCl 的情况下与 Pt 离子反应。在 GRR 中使用 HCl 会导致 AgCl 的快速沉淀，AgCl 在 Ag NCs 表面生长，并充当 Pt 沉积的可移动二级模板。通过控制添加到 Ag NCs 中的 HCl 的量或向反应中引入 PVP 来调节 AgCl 的成核位点的数量。该策略导致形成由一个、两个或多个中空域组成的 Pt/Ag 中空纳米盒、二聚体、多聚体或爆米花形纳米结构。由于存在大的空隙空间和多孔壁，这些纳米结构表现出高表面积和对甲醇氧化反应的改进的催化活性。
