单分散ZnS纳米球与纳米梭之间的形貌转换及光学性能研究

利用平平加作为表面活性剂, 正戊醇作为助表面活性剂, 环己烷作为油相, 以硫化钠(Na₂S)和醋酸锌(Zn(Ac)₂)作为反应物, 通过控制反应条件在反相胶束体系中合成出单分散的ZnS纳米球与纳米梭. 采用XRD和TEM对产物的结构和形貌进行表征, 结果表明产物均为六方相ZnS, 晶胞参数为a＝0.3823 nm, c＝56.2 nm, 纳米球直径约为50 nm, 纳米梭直径约为60 nm, 长度约为110 nm. 采用UV-Vis(紫外可见吸收光谱)和PL(荧光光谱)研究了产物的光学性能. 纳米球的紫外可见光谱的吸收峰出现在288 nm处, 而纳米梭在305 nm处有强吸收峰, 与块体材料相比, 分别有约60和50 nm的蓝移. 当激发波长为270 nm时, 纳米球和纳米梭产物分别能够发出波长为408和303 nm的紫外光.

Morphology Exchange and Optical Properties of Monodispersed ZnS Nanospheres and Nanoshuttles

ZnS nanospheres and nanoshuttles were obtained in a simple reverse micelle system containing cyclohexane as oil phase, aqueous solution 0.1 mol•L^－1 Na₂S and 0.1 mol•L^－1 Zn(OAc)₂] as reactant, n-pentanol as co-surfactant and surfactant (peregals). XRD and TEM were used to characterize the products. The results show that the obtained ZnS nanospheres and nanoshuttles are of hexagonal primitive phase with calculated cell parameters a＝0.3823 nm and c＝56.2 nm. The diameters of the nanospheres are about 50 nm. The nanoshuttles are about 60 nm in diameter with length of about 110 nm. UV-Vis spectrum shows that such ZnS nanospheres and nanoshuttles have absorptions at 288 and 305 nm respectively, which mean about 60 and 50 nm blue shifts from the bulky counterpart. The emission peak appeared at 408 and 303 nm when they were excited at 270 nm. The mechanism of the formation of the nanoshuttles was also explored.