S2-控制剂对Ag纳米产物的形貌及光学性能的影响

摘要

Silver nanostructures were synthesized by decomposing silver sulfide via a modified microwave condensing reflux method by adding sodium sulfide (Na2S) in the presence of polyvinyl pyrrolidone (PVP) as protecting agent and ethylene glycol (EG) as reductant and solvent. The different morphologies of silver nano-products were obtained through changing the concentration of Na2S under the constant parameters such as: heating power, reaction time, surfactant, and reagent concentration. The morphology, crystalline phase, and optical property of the samples were examined by SEM, XRD, and UV-Visible spectrophotometer. The results show that the silver nanoproducts have gone through a spherical-cube-linear evolution in the morphology with gradually increasing Na2S concentration. In addition, the effect of S2- on the morphology of silver nanoproducts and the formation mechanism of silver nanowires are further discussed by analyzing the reaction process and the results obtained in this study.%采用改装的微波冷凝回流装置,以乙二醇作为还原剂和溶剂,在表面活性剂聚乙烯吡咯烷酮的保护下,添加Na2S与AgNO3反应生成Ag2S,对Ag2S进行热分解即可获得Ag纳米产物.保持其它参数(加热功率、加热时间、表面活性剂浓度和反应物溶液浓度等)不变的条件下,通过改变Na2S的浓度得到不同形貌的Ag纳米产物.利用扫描电子显微镜、X射线衍射仪和紫外-可见分析仪对所得Ag纳米产物的形貌、物相和光学性能进行分析表征,结果表明,在微波冷凝回流作用下,Na2S浓度的逐渐增大使银纳米产物经历了一个类球形-立方体-线形的形貌演变.此外,通过分析反应过程,对S2-如何影响Ag纳米产物的形貌及Ag纳米线的生长机理作了进一步研究探讨.