甲烷通气速率/通气量对大量合成SiC一维纳米材料的影响规律

Influence of CH_4 Ventilation Ratio/Ventilation Volume on Synthesis of Large-scale SiC One-dimensional Nanomaterials

采用化学气相反应法(CVR),以球磨后的Si粉、SiO2粉及CH4气体为原料,镍为催化剂,在1 250℃下成功制备出大量SiC一维纳米材料。着重研究了甲烷通气速率/通气量对产物宏观产量、微观形貌的影响规律。采用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)等多种测试手段对所得产物进行了表征。结果表明:随CH4通气速率/通气量的减少,产物宏观颜色由深蓝色转变成灰白色,纳米线直径变得不均匀,纳米线的堆积密度逐渐增大。在通气速率为0.054L·min-1、通气时间36min、通气量1.4L优选工艺条件下,所制备的一维纳米材料为带有少许非晶SiO2包覆层的立方结构的β-SiC。

The SiC one-dimension materials were successfully synthesized by Chemical Vapor Reaction （CVR） approach at 1 250℃. A mixture of milled Si and SiO2 powders and CH4 were selected as starting materials, and Ni was employed as catalyst. The in- fluence of ventilate ratio and ventilation volume on the macroscopic production and mi- crostructure of the product were detailed investigated. The as-prepared products were characterized by digital camera （DG）, scanning electron microscopy （SEM）, transmis- sion electron microscopy （TEM）, X-ray powder diffraction （XRD）. The results show that the macroscopic color of the as-obtained product changes from dark blue to gray- white, the diameter of the nanowires gradually become uneven and the bulk density in- creased with the ventilate ratio/ventilation volume decrease. The nanomaterials obtained under the optimization process conditions of 0. 054 L · min^-1 ventilate ratio, 36 min ven- tilate time and 1.4 L ventilation volume are cubic single crystal 13-SIC with little amor- phous SiO2 wrappers.