Huang Yu-Fen, Huang Kuan-Ming, Chang Huan-Tsung
Department of Chemistry, National Taiwan University, Taipei, Taiwan.
J Nanosci Nanotechnol. 2007 Sep;7(9):3172-9. doi: 10.1166/jnn.2007.687.
This paper describes how irradiation with light influences the preparation of Au-Ag-Hg trimetallic nanoparticles (NPs) from gold nanorods (AuNRs) in glycine solutions (pH 8.5-10.5). Silver, gold, and mercury ions were reduced by ascorbic acid and deposited on AuNRs to form Au-Ag-Hg trimetallic NPs of different sizes and shapes. In addition to the amounts of ascorbic acid, Au seeds, and glycine, others parameters such as pH, irradiation, and the concentrations of Ag, Au, and Hg ions are important for the preparation of these Au-Ag-Hg trimetallic NPs. Transmission electron and dark-field microscopy images indicated that irradiation with light induced the self-assembly of the thus-prepared Au-Ag-Hg trimetallic NPs, in addition to slightly affecting their shapes, but suggested no photoreduction effect during their formation. At pH 10.5, the Au-Ag-Hg trimetallic NPs possessed dumbbell- and millet-like shapes, having the sizes of 51 +/- 3 and 48 +/- 4 nm, respectively, when synthesized in the dark and under illumination, respectively. Time-evolution UV-Vis extinction spectroscopy and inductively coupled plasma mass spectrometry data obtained from solutions at various periods during the formation of the Au-Ag-Hg trimetallic NPs reveal that reduction of the Au and Ag ions occurred prior to reduction of the Hg ions. To the best of our knowledge, this study presents the first example of the light-induced self-assembly of Au-Ag-Hg trimetallic NPs in a liquid phase.
本文描述了光照如何影响在甘氨酸溶液（pH 8.5 - 10.5）中由金纳米棒（AuNRs）制备金 - 银 - 汞三金属纳米颗粒（NPs）。银、金和汞离子被抗坏血酸还原并沉积在AuNRs上，形成不同尺寸和形状的金 - 银 - 汞三金属NPs。除了抗坏血酸、金种子和甘氨酸的用量外，其他参数如pH值、光照以及银、金和汞离子的浓度对于制备这些金 - 银 - 汞三金属NPs也很重要。透射电子显微镜和暗场显微镜图像表明，光照不仅轻微影响所制备的金 - 银 - 汞三金属NPs的形状，还诱导了它们的自组装，但在其形成过程中未显示光还原作用。在pH 10.5时，分别在黑暗中和光照下合成的金 - 银 - 汞三金属NPs具有哑铃状和小米状形状，尺寸分别为51±3和48±4 nm。从金 - 银 - 汞三金属NPs形成过程中不同时期的溶液中获得的时间分辨紫外 - 可见消光光谱和电感耦合等离子体质谱数据表明，金和银离子的还原先于汞离子的还原。据我们所知，本研究首次展示了液相中金 - 银 - 汞三金属NPs的光诱导自组装实例。
