Vacuum Topotactic Conversion Route to Mesoporous Orthorhombic MoO3 Nanowire Bundles with Enhanced Electrochemical Performance

详细信息    查看全文

• 作者：Zhengqiu Yuan ; Lulu Si ; Denghu Wei ; Lei Hu ; Yongchun Zhu ; Xiaona Li ; Yitai Qian
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：March 13, 2014
• 年：2014
• 卷：118
• 期：10
• 页码：5091-5101
• 全文大小：773K
• 年卷期：v.118,no.10(March 13, 2014)
• ISSN：1932-7455

文摘

The growth of mesoporous bundles composed of orthorhombic MoO₃ nanowires with diameters ranging from 10 to 30 nm and lengths of up to 2 渭m by topotactic chemical transformation from triclinic 伪-MoO₃路H₂O nanorods under vacuum condition at 260 掳C is achieved. During the process of vacuum topotactic transformation, the nanorod frameworks of the precursor 伪-MoO₃路H₂O can be preserved. The crystal structures, molecular structures, morphologies, and growth behavior of the precursory, intermediate and final products are characterized using powder X-ray diffraction (PXRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected-area electron diffraction (SAED). Detailed studies of the mechanism of the mesoporous MoO₃ nanowire bundles formation indicate topotactic nucleation and oriented growth of the well-organized orthorhombic MoO₃ nanowires inside the nanorod frameworks. MoO₃ nanocrystals prefer [001] epitaxial growth direction of triclinic 伪-MoO₃路H₂O nanorods due to the structural matching of [001] 伪-MoO₃路H₂O//[100] MoO₃. The electrochemical measurement of the mesoporous MoO₃ nanowire bundles indicates that their galvanostatic Li storage performance can be significantly improved. The high reversible capacities of 954.8 mA h g^鈥? can be retained over 150 cycles. The topotactic growth under vacuum based on the crystal structural relationship of hydrated metal oxide and related metal oxide will provide an effective and all-purpose route to controlled preparation of novel micro/nanostructured oxides (such as V₂O₅ and WO₃ nanowires, etc.) with enhanced properties (energy storage/conversion, organic electronics, catalysis, gas-sensor, and so on).