介观结构SiO_2/CdO纳米复合物为前驱体原位水热合成半导体CdSe和CdS纳米晶

In situ Hydrothermal Synthesis of Semiconductor CdS and CdSe Nanocrystals by Using Mesostructured SiO_2/CdO Composites as Precursor

以高度有序的介观结构SiO2/CdO纳米复合物为前驱体,在硒源或硫源存在的还原性条件下,利用原位水热反应,合成了介观结构SiO2/CdSe及SiO2/CdS纳米复合物,除去SiO2后,得到半导体CdSe及CdS纳米晶.通过X射线衍射(XRD),高分辨率透射电镜(HRTEM),X射线能散射谱(EDX)及选区电子衍射(SAED)等手段对产物进行了组成和结构表征.结果表明,介观结构SiO2主体材料在合成过程中起到了一定的形貌和尺寸限制作用,得到的CdSe和CdS均为直径在8nm左右的类球形六方相纳米晶.

By using mesostructured SiO2/CdO composites as a precursor, uniform sphere-like CdSe and CdS nanocrystals have been synthesized under a reductive condition. In situ hydrothermal phase transition reactions of SiO2/CdO composites with non-metal S or Se were firstly employed. Components and structures of the final products were characterized with X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectra and selected area electron diffraction (SAED). The results show that the mesostructured silica host provides a confinement effect on the size and morphology of the derived nanocrystals. Those CdSe and CdS nanoparticles are both 8 nm in diameter and highly crystallined with hexagonal lattices.