The Fabrication and Characterization of Single-Crystalline Selenium Nanoneedles

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• 作者：Shenglin Xiong ; Baojuan Xi ; Weizhi Wang ; Chengming Wang ; Linfeng Fei ; Hongyang Zhou ; and Yitai Qian
• 刊名：Crystal Growth & Design
• 出版年：2006
• 出版时间：July 2006
• 年：2006
• 卷：6
• 期：7
• 页码：1711 - 1716
• 全文大小：543K
• 年卷期：v.6,no.7(July 2006)
• ISSN：1528-7505

文摘

A solution-phase approach has been demonstrated for large-scale synthesis of selenium nanoneedles with the stemdiameter ranging from 100 to 500 nm and lengths up to tens of micrometers, gradually becoming thinner to form a sharp tip, whichwere fabricated by reduction of Na₂SeO₃ with poly(vinyl alcohol) (PVA). An interesting feature of the nanoneedles is their tendencyto form branches and junctions. The morphology, microstructure, and chemical compositions of the nanoneedles were characterizedusing various methods (XRD, XSP, FESEM, TEM, and high-resolution TEM), indicating that the nanoneedles were single crystallinewith high purity, structurally uniform, and dislocation-free. On the basis of a series of TEM observations, the nucleation and growthprocess of selenium nanoneedles could be interpreted by a solid-solution-solid process and PVA-assisted formation mechanism:trigonal (t)-selenium sphere-like nanoparticles initially formed due to the incessant dissolution of the sphere-like amorphous (a)-selenium nanoparticles in the current hydrothermal process; then the wire-like nanostructures were gradually created from the t-seleniumparticles owing to the intrinsically anisotropic structure of t-selenium. The needle-like end shape was attributed to the higher growthrate on the tip than on the stem of wires since PVA can kinetically control the anisotropic growth via selective absorption ondifferent crystalline faces.