Growth of SiO2 nanowires without a catalyst via carbothermal reduction of CuO powders
Growth of SiO2 nanowires without a catalyst via carbothermal reduction of CuO powders
复制标题
无催化剂通过 CuO 粉末碳热还原生长 SiO2 纳米线
DOI：
--
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
Wen
中科院分区：
文献类型：
--
作者：
Yu;Wen
研究了碳热还原法制备SiO2纳米线（SiONWs）的工艺条件，考察了Ar流量、CuO/碳粉中碳浓度和Ar/O2流量中氧浓度对SiO2纳米线生长的影响。在没有催化剂的情况下，在1000-1100 °C的温度下，在流速为100 sccm的流动Ar中，在Si衬底上从CuO/碳粉生长大量的SiONW。在不使用CuO/碳粉的情况下，不能容易地生长SiONW。少量的SiC与SiONWs生长从CuO/碳粉与较高比例的碳。SiONWs生长所需的最小Ar流量约为10 sccm，SiONWs的数量和直径随着Ar流量的增加而增加，表明Ar流量辅助的气相输运是SiONWs成核和生长的重要机制。SiONW的生长主要源于CO2与Si衬底反应生成的SiO（g）在Si衬底上形成的裂纹。将O2引入到Ar流中可以产生显著量的CO，从而抑制SiONW的生长。研究表明，CuO碳热还原法制备SiONW主要遵循气-固反应机理。
The growth of SiO2 nanowires (SiONWs) via carbothermal reduction of CuO powders as functions of the Ar flow rate, the carbon concentration in the CuO/carbon powders, and the oxygen concentration in the Ar/O2 flow was studied. Significant amounts of SiONWs were grown on the Si substrate without a catalyst from CuO/carbon powders at a temperature of 1000–1100 °C in flowing Ar with the flow rate of 100 sccm. Without using CuO/carbon powders SiONWs could not be readily grown. A small amount of SiC associated with SiONWs was grown from CuO/carbon powders with a higher proportion of carbon. The minimum Ar flow rate required for the growth of SiONWs was about 10 sccm and the amount as well as the diameter of the SiONWs increased with increase of the Ar flow rate, revealing that vapour transport assisted by Ar flow is an important mechanism for the nucleation and growth of SiONWs. The growth of SiONWs mainly originated in the cracks which were formed in the Si substrate due to the generation of SiO(g) from the reaction between CO2 and the Si substrate. The introduction of O2 into the Ar flow could generate a significant amount of CO and thereby suppress the growth of SiONWs. The present studies reveal that the growth of SiONWs via carbothermal reduction of CuO powders mainly follows the vapour–solid mechanism.