Fundamental Strategy for Creating VLS Grown TiO2 Single Crystalline Nanowires

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• 作者：Fuwei Zhuge ; Takeshi Yanagida ; Kazuki Nagashima ; Hideto Yoshida ; Masaki Kanai ; Bo Xu ; Annop Klamchuen ; Gang Meng ; Yong He ; Sakon Rahong ; Xiaomin Li ; Masaru Suzuki ; Shoichi Kai ; Seiji Takeda ; Tomoji Kawai
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：November 15, 2012
• 年：2012
• 卷：116
• 期：45
• 页码：24367-24372
• 全文大小：552K
• 年卷期：v.116,no.45(November 15, 2012)
• ISSN：1932-7455

文摘

A single crystalline TiO₂ nanowire grown by a size and position controllable vapor鈥搇iquid鈥搒olid (VLS) method is a promising candidate to control and design the physical and chemical properties for various TiO₂-based applications. However, creating TiO₂ nanowires by VLS has been a challenging issue due to a difficulty on controlling and understanding the complex material transport events across three phases. Here we propose a fundamental strategy to create a TiO₂ single crystalline nanowire by the VLS mechanism. We show that a VLS growth of TiO₂ nanowires can emerge intrinsically only within a quite narrow range of material flux, which is a sharp contrast to typical VLS oxides including MgO, SnO₂, In₂O₃, and ZnO, whose nanowires are easily grown by VLS with much wider ranges of material flux. We reveal that a condensation of Ti atoms at a vapor鈥搒olid interface, which is detrimental for VLS, is responsible to limit a window of material flux for TiO₂ nanowires. In addition, we found that our rutile-TiO₂ nanowires preferentially grow along 001 direction, which interestingly differs from a typical 110 oriented growth of TiO₂ nanowires formed by the vapor-phase method. The present approach based on a control of material flux provides a foundation to tailor VLS grown TiO₂ nanowires based on a scientific strategy rather than a rule of thumb.