氧化银纳米线在官能化二氧化硅颗粒表面的自组装合成

Ag_2O Nanowires Self-assembled on Amino-functionalized Silica Nanoparticles

在碱性水醇溶液中,硝酸银与用3-(2-氨乙基氨丙基)三甲氧基硅烷[N-(2-aminoethyl)-3-aminopropyl-trimethoxy- silane,AMPTS]表面修饰后的二氧化硅胶体颗粒相互作用,发现所生成的氧化银纳米颗粒可以在二氧化硅颗粒表面自组装为氧化银纳米线。通过调变反应物中Ag/Si摩尔比,可对氧化银纳米线的形貌进行调控,在较小的Ag/Si摩尔比下,可以得到结构均匀、直径约为50nm、长度几十微米的氧化银纳米线.随Ag/Si摩尔比增大,得到的氧化银纳米线逐渐变短变粗,且结构变得不均匀.高分辨透射电镜(HRTEM)显示,所有的氧化银纳米线均由直径10～20nm的氧化银颗粒定向堆积而得.利用透射电镜(TEM)对氧化银纳米线的形成过程进行了观察,并对氧化银颗粒形成及组装机理进行了探讨。

This research described a novel self-assembling process from Ag2O nanoparticles into Ag2O nanowires and their growth mechanism. In the basic water-alcohol solution, Ag2O nanoparticles came into being while AgNO3 interacted with the silica nanoparticles surface-functionalized by N-（2-aminoethyl）-3- aminopropyl-trimethoxysilane （AMPTS）. The formed Ag2O nanoparticles further self-assembled into Ag2O nanowires on the surface functionalized silica. The shape and size of Ag2O nanowires could be controlled by adjusting the molar ratios of Ag/Si in the reactants. Under the lower molar ratio of Ag/Si, uniform Ag2O nanowires with diameter of about 50 nm and length of several tens micrometers were obtained. With the higher molar ratio of Ag/Si, Ag2O nanowires became thicker, shorter and irregular. However, it was shown by HRTEM that all Ag2O nanowires consisted of tiny Ag2O particles with diameter of 10～20 nm. The whole process of Ag2O nanoparticles forming and self-assembling into Ag2O nanowires was observed by TEM and the corresponding growth mechanism was further investigated.