Song Hyunjoon, Kim Franklin, Connor Stephen, Somorjai Gabor A, Yang Peidong
Department of Chemistry, University of California, Berkeley, Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
J Phys Chem B. 2005 Jan 13;109(1):188-93. doi: 10.1021/jp0464775.
We report the synthesis of monodisperse Pt nanocrystals with three different shapes-cubes, cuboctahedra, and octahedra, selectively, with similar sizes of 9-10 nm by a modified polyol process. We found that addition of silver ion enhances the crystal growth rate along 100, and essentially determines the shape and surface structure of the Pt nanocrystals. After the reaction, the silver species can be easily removed by repetitive precipitation giving pure Pt nanoparticles. Two-dimensional arrays of the Pt nanocrystals were assembled by using the Langmuir-Blodgett (LB) method. The particles were evenly distributed on the entire substrate, and their surface coverage and density can be precisely controlled by tuning the surface pressure. The resulting Pt LB layers are potential candidates for 2-D model catalysts as a result of their high surface area and the structural uniformity of the metal nanocrystals.
我们报道了通过改进的多元醇法选择性地合成具有三种不同形状（立方体、立方八面体和八面体）、尺寸相似（9 - 10纳米）的单分散铂纳米晶体。我们发现银离子的加入提高了沿<100>方向的晶体生长速率，并基本上决定了铂纳米晶体的形状和表面结构。反应后，通过反复沉淀可以轻松去除银物种，从而得到纯的铂纳米颗粒。利用朗缪尔 - 布洛杰特（LB）法组装了铂纳米晶体的二维阵列。颗粒均匀分布在整个基底上，通过调节表面压力可以精确控制它们的表面覆盖率和密度。由于其高表面积和金属纳米晶体的结构均匀性，所得的铂LB层是二维模型催化剂的潜在候选材料。
