期刊
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
卷 302, 期 1-3, 页码 587-598出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.colsurfa.2007.03.044
关键词
Au nanocrystal; microwave-polyol method; oxidative etching; Cl- anion
Shape and size controlled synthesis of gold nanocrystals have been studied by using a microwave (MW)-polyol method. When Au3+ in HAuCl4 center dot 4H(2)O was reduced in ethylene glycol (EG) in the presence of poly(vinylpyrrolidone) (PVP) at a low HAuCl4 concentration, mixtures of spherical, triangular, octahedral, and decahedral particles were prepared in a few minutes. It was found that the shape selective oxidative etching by AUCl(4)(-) + Cl- anions and crystal growth occurred simultaneously at high HAuCl4 concentrations. The addition of MCl (M = Na, K, H) was very effective to enhance the shape selective oxidative etching by AuCl4- + Cl- anions. With increasing the AUCl(4)(-) and Cl- concentrations, yields of large plate-type and ribbon-type single twin particles increased, while those of spherical and octahedral particles decreased in most cases. Possible etching and growth mechanisms are discussed from dramatic color and absorption spectral changes of An seeds in the HAuCl4 center dot 4H(2)O/PVP/EG solution with increasing the solution temperature and from TEM images before and after oxidative etching. The present results provide a new simple technique for the rapid shape and size controlled synthesis of Au nanocrystals under MW heating. (C) 2007 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据