ZnO-TiO2核壳纳米线结构及其热稳定性研究

Structure and Thermal Stability of ZnO-TiO2 Core-Shell Nanowires

摘要:

采用热还原法和原子层沉积技术制备了ZnO-TiO2核壳纳米线，研究沉积厚度、沉积温度及退火对于ZnO-TiO2核壳纳米线晶化和结构的影响。利用X射线衍射（XRD）、扫描电子显微镜（SEM）、高分辨率透射电镜（HRTEM）等手段对退火前后核壳纳米线进行表征。结果表明：沉积厚度和温度的增加有利于TiO2壳层发生非晶向晶化的转变；500 ℃退火提高了TiO2的结晶性，但可能会使细核壳纳米线（ZnO纳米线直径<80 nm）产生波浪形变形，使150 ℃沉积的非晶TiO2壳层形成凸出晶粒，并导致其界面处ZnO缺失

Abstract:

ZnO-TiO2 core-shell nanowires were prepared by a thermal reduction method and an atomic layer deposition (ALD) technique. The effects of deposition thickness, deposition temperature and annealing on crystallization and structure of ZnO-TiO2 core-shell nanowires were studied. ZnO-TiO2 core-shell nanowires were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM). The results show that TiO2 shell is transformed from amorphous to crystallization with the increasing of the deposition thickness and deposition temperature. After 500 oC annealing, the crystallinity of TiO2 shell is improved, but wavy deformation is observed in the fine core-shell nanowires (the diameter of ZnO nanowires < 80 nm). As for amorphous TiO2 shell deposited at 150 oC after 500 oC annealing, convex grains are formed on the TiO2 shell and the loss of ZnO appears at the ZnO-TiO2 interface