Hydrothermal synthesis of single-crystalline anatase TiO2 nanorods with nanotubes as the precursor
Hydrothermal synthesis of single-crystalline anatase TiO2 nanorods with nanotubes as the precursor
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DOI：
10.1021/jp0567321
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发表时间：
2006-03-09
影响因子：
3.3
通讯作者：
Teng, HS
中科院分区：
文献类型：
--
作者：
Nian, JN;Teng, HS
在没有表面活性剂或模板的情况下从溶液中制备锐钛矿型 TiO2 纳米棒的报道很少。目前的工作发现，在酸性环境下对钛酸盐纳米管悬浮液进行水热处理导致形成具有特定晶体伸长方向的单晶锐钛矿纳米棒。通过在 NaOH 中处理 TiO2，然后与 HNO3 混合至不同的 pH 值来制备纳米管悬浮液。水热处理得到的锐钛矿纳米粒子的晶体尺寸随着悬浮液的pH值而增大，在pH值略小于7时获得了长径比高达6且长轴沿锐钛矿[001]的纳米棒。基于管和棒的晶体结构，提出了管棒转变的机制。管壁的局部收缩形成锐钛矿微晶以及随后微晶的定向附着被认为是纳米棒形成中涉及的关键步骤。
Preparation of anatase TiO2 nanorods from solutions in the absence of surfactants or templates has rarely been reported. The present work has found that hydrothermal treatment of titanate nanotube suspensions under an acidic environment resulted in the formation of single-crystalline anatase nanorods with a specific crystal-elongation direction. The nanotube suspensions were prepared by treatment of TiO2 in NaOH, followed by mixing with HNO3 to different pH values. The crystal size of the anatase nanoparticles obtained from the hydrothermal treatment increased with the pH of the suspensions, and nanorods with an aspect ratio up to 6 and a long axis along the anatase [001] were obtained at a pH slightly less than 7. A mechanism for the tube-to-rod transformation has been proposed on the basis of the crystalline structures of the tubes and rods. The local shrinkage of the tube walls to form anatase crystallites and the subsequent oriented attachment of the crystallites have been suggested to be the key steps involved in the nanorod formation.