Direct Electrolytic Reduction of Solid Silicon Dioxide in Molten LiCl – KCl – CaCl2 at 773 K
Direct Electrolytic Reduction of Solid Silicon Dioxide in Molten LiCl – KCl – CaCl2 at 773 K
复制标题
DOI：
10.1149/1.2042910
复制
发表时间：
2005-11
影响因子：
3.9
通讯作者：
K. Yasuda;T. Nohira;Y. Ogata;Y. Ito
中科院分区：
文献类型：
--
作者：
K. Yasuda;T. Nohira;Y. Ogata;Y. Ito
我们研究了在 773 K 熔融 LiCl-KCl-CaCl 2 中通过接触电极法电解还原固体 SiO 2 。循环伏安法的结果表明，SiO 2 的还原发生在比 0.85 V 更负的电位（相对于 Ca 2 + 、Li + /Ca-Li）。通过在0.25、0.50、0.70和1.00 V下恒电位电解2 h制备样品。能量色散X射线分析和拉曼光谱表明，0.50和0.70 V下的还原产物由非晶硅和微晶硅组成。扫描电子显微镜（SEM）观察表明，生成的Si形貌呈海绵状，粒径小于50 nm。通过比较773和1123 K下制备的Si样品的SEM观察结果和拉曼光谱，讨论了Si的形成机理。还讨论了在较低温度下直接电解还原SiO 2 的还原机理。
We investigated electrolytic reduction of solid SiO 2 by a contacting electrode method in molten LiCl-KCl-CaCl 2 at 773 K. The results of cyclic voltammetry indicated that reduction of SiO 2 occurs at potential more negative than 0.85 V (vs Ca 2 + , Li + /Ca-Li). Samples were prepared by potentiostatic electrolysis for 2 h at 0.25, 0.50, 0.70, and 1.00 V. Energy dispersive X-ray analysis and Raman spectra clarified that the reduction products at 0.50 and 0.70 V are composed of amorphous Si and microcrystalline Si. Scanning electron microscope (SEM) observations revealed that the morphology of the produced Si is spongelike with a particle size smaller than 50 nm. The mechanism of Si formation was discussed by comparing the SEM observations and the Raman spectra of the Si samples prepared at 773 and 1123 K. The reduction mechanism of the direct electrolytic reduction of SiO 2 at lower temperature was also discussed.