以氯金酸(HAu Cl4)为前驱物,油胺同时作为溶剂、表面稳定剂和还原剂,通过简单的一步湿化学法合成超细金纳米线.制备出的超细金纳米线不仅产量高、纯度高,而且纵横比大,纳米线平均直径~2 nm,长度可达数十微米.如果添加另一种还原剂油酸并调节油胺和油酸的体积比为1:1,将生成直径为~9 nm的金纳米线.通过改变反应温度和还原剂用量,对该种超细金纳米结构的生长机制进行阐述说明:以油胺为模板,在油胺和一价金卤化物(Au Cl)亲金键合形成的一维聚合链作用下,被还原的金原子附着在已成核颗粒表面,一维地生长成超细金纳米线.
Ultrafine Au nanowires (AuNWs) were synthesized in high yields by a one-step wet chemical method using oleylamine as the solvent, surfactant, and reductant. The obtained AuNWs were of high purity and had a high aspect ratio, with diameters of ~2 nm and lengths of tens of micrometers. AuNWs of diameter ~9 nm were also obtained in the presence of oleic acid, at an oleic acid:oleylamine volume ratio of 1:1. The formation of AuNWs was studied by changing the reaction temperature and the volume of oleylamine. It is proposed that the growth mechanism of the Au nanostructures involves strong aurophilic interactions from oleylamine-AuCI complexes; the reduced Au atoms agglomerate and attach to preformed particles, and the oleylamine molecular layer acts as a soft template, leading to one-dimensional growth of Au atoms into AuNWs.