室温合成硫化银纳米粒子及其X射线光电子能谱表征

Synthesis of Ag_2S Nanoparticles at Room Temperature and TheirCharacterization with XPS

在常温常压下制备了硫化银纳米粒子,选用廉价的氧化银和硫粉为原料,采用多聚甲醛为还原剂,并在乙二胺体系中完成了反应。所得产物用X射线光电子能谱、X射线粉末衍射和透射电镜进行了表征。X射线粉末衍射表明:产物为单斜相的硫化银;透射电子显微镜表明:产物为直径约为10 0nm的棒状纳米粒子,其对应的电子衍射斑点可以指标成(12 0 )和(3- 0 3) ,说明产物的结晶较好;X射线光电子能谱分析表明:产物中Ag属+1价而S属- 2价,它们的原子个数比为Ag∶S =1∶0. 4 5 3。对比实验表明:多聚甲醛和无水乙二胺都起了很关键的作用;多聚甲醛起了多重作用,它既是溶剂,又是中和剂,用以除去反应的副产物多个点 甲酸,从而加速了反应的进行。

Nanocrystalline silver sulfide was successfully synthesized at room temperature and ambient pressure via a novel, safe, convenient and inexpensive redox reaction, using silver oxide, sulfur and polyformaldehyde as reactants and ethylenediamine as solvent. The products were characterized with XPS, XRD and TEM. XRD spectrum demonstrates a monoclinic Ag-2 S; TEM shows the products are rod-like nanoparticles with average diameter of 100 rim, its corresponding SAED reveals clear diffraction spots indexed as (120) and (303); XPS confirms the formation of Ag2 S and indicates the sample's surface stoichiometry of Ag: S=1:0.453. The control experiments show polyformalclehyde and ethylenediamine are both important in the fonnation of products. Ethylenediamine accelerates the reactions via dissolving silver oxide and sulfur and neutralizing the by-product formic acid.