边长为微米级的银纳米片的简易合成与形成机理

用低温(60 ℃)溶剂热法, 以N,N-二甲基甲酰胺(DMF)为主还原剂和溶剂, 以聚乙烯吡咯烷酮(PVP)为辅助还原剂和晶面生长控制剂, 以硝酸银为前驱物, 大量制备了高纯度的、边长为微米级、宽厚比≥10的单晶银纳米片. 采用粉末X射线衍射(PXRD)、场发射扫描电镜(FE-SEM)、透射电子显微镜(TEM)等表征和分析了合成产物的成分、形貌和结构. 结果表明, 合成的银纳米片为面心立方单晶, 边长为1-4 μm, 厚度为50-100 nm. 考察了不同溶剂对银纳米结构的影响, 并提出了大尺寸的银纳米片的形成机理. 本文为调控单晶银纳米片的边长和宽厚比提供了一种新的可靠的动力学方法, 制备的长边长、大宽厚比的单晶银纳米片在聚合物基导电复合材料和电磁屏蔽材料方面有潜在的重要应用.

Facile Synthesis and Formation Mechanism of Silver Nanoplates with Edge Lengths of Several Micrometers

We developed a low temperature solvothermal approach to synthesize single crystal silver nanoplates with edge lengths of 1-4 μm, thicknesses of 50-100 nm and aspect ratios ≥10 in a large-scale. In this solvothermal approach, N,N-dimethyllformamide (DMF) was used as a main reducing agent and as a solvent, polyvinylpyrrolidone (PVP) was used as a supplementary reducing agent and capping agent, and silver nitrates were used as precursors. The as-obtained silver products of high-purity were characterized by powder X-ray diffraction (PXRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). We investigated the impact of different solvents on the morphologies of these silver nanostructures and proposed a possible growth mechanism for the as-synthesized silver nanoplates with large edge lengths and high aspect ratios. The current work provides a new reliable kinetic approach to tune the edge lengths and aspect ratios of silver nanoplates. The as-obtained silver nanoplates with large edge lengths and high aspect ratios have potential important application in polymer-based conductive composites and electromagnetic shielding materials.