( 1. 西安交通大學(xué) 理學(xué)院， 西安 710049;
2. 中北大學(xué) 物理系， 太原 030051)
摘 要: 以NaHB4做還原劑， 利用一步共還原氯金酸(HAuCl4)和硝酸銀(AgNO3)制備了金-銀復(fù)合結(jié)構(gòu)的納米顆粒。 用透射電子顯微鏡對(duì)所制備的金-銀復(fù)合納米微粒的形貌和尺寸進(jìn)行了表征。紫外-可見光學(xué)吸收光譜的研究表明： 通過一步共還原法所制備的金-銀復(fù)合納米微粒的光學(xué)吸收譜具有單峰的等離子體吸收特征，其吸收峰介于純金和純銀納米顆粒特征吸收峰之間, 且隨著反應(yīng)液中金離子和銀離子的摩爾比的增加而向長(zhǎng)波方向移動(dòng)。 Mie散射理論的定量計(jì)算結(jié)果同樣說明了實(shí)驗(yàn)所觀察到的金-銀復(fù)合納米微粒的光學(xué)吸收的組分可剪裁性。
關(guān)鍵字: 金-銀復(fù)合納米顆粒； 光學(xué)吸收光譜； Mie散射理論
Au-Ag composite nanoparticles
（1. School of Science, Xi'an Jiaotong University, Xi'an 710049, China;
2. Department of Physics, North University of China, Taiyuan 030051, China）
Abstract: Au-Ag composite nanoparticles were synthesized by simultaneously reduction of HAuCl4 and AgNO3 using NaHB4 as reducing agent. The morphology and size of the particles were measured by the transmission electron microscopy (TEM). UV-vis absorption spectra results show that Au-Ag composite nanoparticles prepared by the one step co-reduction method have only one plasmon absorption band. The maximum absorption peak of Au-Ag composite nanoparticles between the absorption peaks of pure gold and pure silver nanoparticles and shift towards longer wavelength with increasing the molar ratio of Au and Ag ions in the reaction solution. The numerical analysis results based on the Mie scattering theory quantitatively account for the observed optical absorption properties dependence on the composition of Au-Ag composite nanoparticles.
Key words: Au-Ag composite nanoparticles; optical absorption spectra; Mie scattering theory
