Fe-Assisted Synthesis of Si Nanowires

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• 作者：Iftikhar Ahmad ; Michael Fay ; Yongde Xia ; Xianghui Hou ; Andrew Kennedy ; Yanqiu Zhu
• 刊名：Journal of Physical Chemistry C
• 出版年：2009
• 出版时间：January 29, 2009
• 年：2009
• 卷：113
• 期：4
• 页码：1286-1292
• 全文大小：346K
• 年卷期：v.113,no.4(January 29, 2009)
• ISSN：1932-7455

文摘

Ultrafine and pure Si-nanowires (SiNWs) have been synthesized with the assistance of carbon nanotubes (CNTs) during a chemical vapor deposition process via the vapor liquid solid (VLS) mechanism. A mixture of CNTs and Si₃N₄ produces a high yield of fine SiNWs upon heating at 1600 °C under Ar atmosphere. Fe nanoparticles, located at the tip of CNTs, have been employed as a catalyst for the growth of nanowires and carbon acted as a reducing agent during the synthesis process. The resulting SiNWs have been appraised by SEM, TEM, XRD, Raman, BET, and FTIR to investigate the morphology, structure, and surface characteristics. Electron microscopic studies have demonstrated that the SiNWs have a uniform diameter of 7−17 nm, being single crystalline and enveloped with a tiny sheath of SiO_x (x = 12). Furthermore, hydrofluoric acid etching can remove the oxide shell, leading to much purer and finer SiNWs. Nitrogen-sorption isotherms indicate that SiNWs have very high BET specific surface areas. The high yield, ultrafine size, and large surface areas cumulatively offer these nanowires a great potential as candidates for advanced applications in nanodevices, fuel cells, and catalysis.