热处理对CuO纳米线生长的影响

Effect of heat treatment on the growth of CuO nanowires

本文通过热氧化法制备了CuO纳米线,利用X射线衍射和扫描电子显微镜,研究了温度和冷却方式对CuO纳米线生长的影响。600℃空冷样品只长出了少量CuO纳米线,600℃炉冷样品上观察到了大量CuO纳米线,400℃空冷样品上也生长了大量CuO纳米线,表明CuO纳米线的实际生长温度不高于400℃。温度比较高时,以CuO层的生长为主;在温度比较低时,以CuO纳米线的生长为主。这一结果可以通过铜离子在氧化层中的扩散过程来理解。

In this paper,CuO nanowires were prepared by thermal oxidation method. The effect of temperature and cooling methods on the growth of CuO nanowires were studied through scanning electron microscopy and X-ray diffraction. A few CuO nanowires were obtained in the air cooling sample after heating at 600 ℃,while a large number of CuO nanowires were observed in sample cooling in furnace at 600 ℃. Besides,there were many nanowires in the air cooling sample after heating at 400 ℃. It could be concluded that the growth temperature of CuO nanowires was not higher than 400 ℃. CuO layer got growth when the temperature was higher than 400 ℃,and the growth of CuO nanowires mainly occurred at lower temperature. These results could be understood by the diffusion of Cu ion in the oxidation layer. The main diffusion ways of Cu ion are lattice diffusion and grain boundary diffusion,which correspond to the higher temperature and the lower temperature,respectively. Lattice diffusion would result in the growth of CuO layer while grain boundary diffusion would result in the growth of CuO nanowires.