反应性模板法合成硫化银中空球-银纳米粒子异质结构

以Cu₂S中空球为反应性模板, 通过在水溶液中与银离子的阳离子交换和氧化还原反应制备了大小均匀的Ag₂S中空球-Ag纳米粒子异质结构, 即Ag₂S-Ag异质中空球. 该异质结构中每个Ag₂S中空球的直径约为600 nm, 壁厚约20–30 nm, 其表面均附着一个Ag纳米粒子. 采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射(XRD)和能量色散X射线谱(EDS)对所得Ag₂S-Ag异质中空球的结构和组成进行了表征. 若以CuS中空球为反应性模板, 在相似转化条件下则主要得到不含Ag粒子的Ag₂S中空球. 该结果表明, Cu₂S中的Cu(I)的还原性在Ag₂S-Ag异质中空球的形成中发挥了重要作用. 通过对所制备的Ag₂S-Ag异质中空球进行二次生长, 还可以得到Ag₂S中空球的半球表面均被Ag膜所包覆的Ag₂S-Ag异质中空球.

Synthesis of Silver Sulfide Hollow Sphere-Silver Nanoparticle Heterostructures Based on Reactive Templates

Silver sulfide hollow sphere-silver nanoparticle heterostructures were prepared by the simultaneous cation exchange and oxidation-reduction reactions of Cu₂S hollow spheres with Ag⁺ ions in aqueous solution. The obtained Ag₂S-Ag hybrid hollow spheres consisted of Ag₂S hollow spheres about 600 nm in diameter and 20-30 nm in thickness with a single Ag nanoparticle attached to the outer surface of each Ag₂S hollow sphere. The products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray spectroscopy (EDS). When CuS hollow spheres were used as the reactive template instead of Cu₂S hollow spheres, Ag₂S hollow spheres were the predominant product under similar reaction conditions, indicating that the Cu(I) in the Cu₂S hollow spheres served as a reductant for reducing Ag⁺ ions to metallic Ag, and hence played a key role in the formation of the Ag₂S-Ag hybrid hollow spheres. Furthermore, secondary deposition of Ag on the Ag₂S-Ag hybrid hollow spheres resulted in the formation of larger Ag₂S-Ag hybrid hollow spheres consisting of Ag₂S hollow spheres with around a half of the surface coated by a Ag film.