Abstract

Sphere-like silver nanostructures composed of self-assembled nanosheets were rapidly synthesized through adding ferrous sulfate into the mixture of silver nitrate and citric acid aqueous solution by magnetic stirring at room temperature for 20 min. The effects of the concentrations of the ferrous sulfate and citric acid on the morphology of the silver nanostructures were investigated in detail. The characterization of the sphere-like silver nanostructures composed of self-assembled nanosheets have been discussed by scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and differential scanning calorimetry. Furthermore, the possible formation mechanism of sphere-like silver nanostructures composed of self-assembled nanosheets was explored. The experimental results show that the high concentration of citric acid and the low concentration of ferric sulfate are better for obtaining the sphere-like silver nanostructures composed of self-assembled nanosheets due to a low diffusion rate of silver atoms to the silver nucleus and a low growth rate of silver flakes along the {111} facets. Such sphere-like silver nanostructures exhibit a strong surface-enhanced Raman scattering effect associated with their geometries, which is much stronger than that from nanosheets.

中文翻译：

---

自组装纳米片组成的类似球形的银纳米结构的合成

摘要

通过在室温下磁力搅拌20分钟将硫酸亚铁添加到硝酸银和柠檬酸水溶液的混合物中，可以快速合成由自组装纳米片组成的球形银纳米结构。详细研究了硫酸亚铁和柠檬酸的浓度对银纳米结构形态的影响。通过扫描电子显微镜，X射线衍射，X射线光电子能谱和差示扫描量热法已经讨论了由自组装纳米片组成的球形银纳米结构的表征。此外，探索了由自组装纳米片组成的球形银纳米结构的可能形成机理。实验结果表明，高浓度的柠檬酸和低浓度的硫酸铁由于获得的银原子向银核的扩散速率低，且原子序数低，因此更易于获得由自组装纳米片组成的球形银纳米结构。 {111}面的银薄片的生长速率。这种球形银纳米结构表现出与它们的几何形状相关的强表面增强的拉曼散射效应，这比纳米片的强得多。