液固相水热法制备氧化硅纳米线

Hydrothermal Synthesis of Silicon Oxide Nanowires in Solid-liquid Phase System

利用液固相水热反应方法,以硅溶胶为硅源,在三价铁辅助下与乙二胺的水溶液在180℃反应4d后生成具有P21212空间群结构的单晶氧化硅纳米线.用扫描电子显微镜、透射电子显微镜和多晶X射线衍射对制备的样品进行了表征,系统研究了有机胺、金属盐、反应时间及反应温度等条件对氧化硅纳米线生长的影响.结果表明,随着有机胺碳链的增长,产物形貌逐渐由纳米线转变为纳米片;金属阳离子的存在对纳米线形貌有较大的影响,而阴离子的存在并不影响纳米线的生成;过低的铁含量导致反应进行不完全,而过多的铁盐加入则会导致反应中剩余铁氧化物吸附到氧化硅纳米线表面,进而影响到产物纯度;反应时间延长及反应温度的提高都有利于氧化硅纳米线的生长.最佳反应条件为:有机胺为乙二胺,硝酸铁为铁源,硅溶胶为硅源,硅/铁摩尔比为1∶0.4,乙二胺与水的体积比为8∶5,温度为180℃.

In this paper,silicon oxide nanowires with P21212 space group were synthesized by liquid-solid phase hydrothermal method,using silica sol,Fe（NO3）3／59H2O and ethylenediamine-water solution as raw materials.Their structures were characterized by SEM,TEM,XRD and EDS.It was found that the reaction activity could be improved due to the employment of suitable silica and iron resources.As a result,the reaction conditions became more moderate,and less Fe species was used.An optimum experimental condition could be obtained,that is,the Si/Fe molar ratio of 1∶0.4,the ethylenediamine/water volume ratio of 8∶5,the temperature of 180 ℃ and the reaction time of 4 d.This approach is expected to provide a huge possibility for the industrialized manufacture of silicon oxide nanowires.