Repair the Pores and Preserve the Morphology: Formation of High Crystallinity 1D Nanostructures via the Thermal Conversion Route

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• 作者：Wancheng Zhu ; Qiang Zhang ; Lan Xiang ; Shenlin Zhu
• 刊名：Crystal Growth & Design
• 出版年：2011
• 出版时间：March 2, 2011
• 年：2011
• 卷：11
• 期：3
• 页码：709-718
• 全文大小：1365K
• 年卷期：v.11,no.3(March 2, 2011)
• ISSN：1528-7505

文摘

Hydrothermal synthesis (and other soft chemistry based thermal conversion routes) has emerged as one of the thriving methods for high quality one-dimensional (1D) nanostructures. However, it is still a great challenge to repair the pores and preserve the 1D morphology during the thermal conversion. The effects of the heating procedures, especially the flux agent on the calcined Mg₂B₂O₅ nanowhiskers based on the hydrothermally synthesized MgBO₂(OH) nanowhiskers, have been investigated. By using the CCD camera aided in situ dynamic observation, the thermal decomposition of MgBO₂(OH) nanowhiskers is discovered for the first time. With the dehydration going on, pores are generated, coalesced, ruptured, migrated, and finally evaporated out of the bulk of the nanowhiskers. Meanwhile, the molten flux agent penetrates into the bulk of the nanowhiskers through the microchannels exposed onto the surfaces and further flows to each point to which the pores migrate. During the recrystallization, the flux is extruded out to the surfaces and finally washed out via post-treatment. The flux agent serves as the ideal liquid medium for the rearrangement of Mg₂B₂O₅, through which the pores formed during the dehydration are repaired and the overall 1D morphology is preserved. This is helpful to further understand the fantastic formation and thus contributes to the state-of-the-art controllable synthesis of pore-free high crystallinity 1D anhydrous nanostructures via the hydrothermal or other soft chemistry based thermal conversion routes.