Uniform CdS colloidal spheres have been successfully synthesized via a simple hydrothermal method. X-ray diffraction （XRD） analyses indicate that the products exhibit a hexagonal structure. Scanning electron （SEM） and transmission electron microscopy （TEM） are used to characterize CdS colloidal spheres. The final size of the spheres may be selected from a range of 71± 2 nm to approximately 181 ± 5 nm by changing the amount of polyvinylpyrrolidone （PVP） and hexamethylenetetramine （HMT）. The CdS colloidal spheres are not obtained in the absence of either of the capping agents. A synergistic effect between HMT and PVP is proposed to be crucial for the formation of colloidal spheres.
Xiu Jie YangXin Ping LiXiang Tao BaiLi Qiang Zheng
Silver nanorods have been successfully synthesized in large scale by the ethylene glycol（EG） reduction in the presence of ionic liquid（IL） 1-butyl-3-methylimidazolium tetrafluoroborate（bmimBF_4） and polyvinyl-pyrrolidone（PVP）.The silver nanorods were characterized by scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,transmission electron microscopy（TEM）,electron energy disperse spectroscopy（EDS） and UV-vis spectroscopy.The results showed that the uniform silver nanorods have an average diameter of about 100 nm and the aspect ratio from 15 to 20.IL,bmimBF_4 may play a role of capping agent together with PVP in the formation of silver nanorods.On the other band,bmimBF_4 may accelerate nucleation and improve the stability of the resulting Ag nanorods due to the low interface tension of IL.
Hong Ying Wang Yan An Gao Ming Wei Zhao Li Qiang Zheng
