This paper describes a solution-phase hydrothermal synthesis of crystalline niobium pentoxide (Nb₂O₅) nanorods. The methods reported herein yield uniform Nb₂O₅ nanorods with average diameters of 6 nm and lengths of 38 nm, which are directly synthesized from niobic acid by a hydrothermal process. The formation of Nb₂O₅ nanorods from niobic acid was studied in the presence of surfactants that stabilize the nanostructures. The crystalline Nb₂O₅ nanorods were relatively uniform in size and shape. The size of the Nb₂O₅ nanorods could be tuned through the choice of surfactant even in the absence of a worm-like micellar morphology. Amine, amide, ammonium, carboxylate, sulfonate, and sulfate containing surfactants were systematically evaluated for their influence on the ability to form uniform Nb₂O₅ nanorods. The surfactants in this study had hydrophobic tails that were either straight or branched, such as a polymer, and contained either a single or multiple head groups. The nanorods grew by a process of oriented attachment of nanoparticles that was regulated by the surfactants added into the reaction mixture. The results of these studies indicate that this synthetic approach serves as a tunable platform to prepare single crystalline niobium oxide based nanostructures with well-defined morphologies and dimensions. This surfactant assisted formation of crystalline Nb₂O₅ nanorods could also have important implications in the design of other transition metal oxide based nanomaterials.

中文翻译：

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表面活性剂控制氧化铌纳米棒的生长

本文介绍了溶液相水热法合成五氧化_二铌（Nb ₂ O ₅）纳米棒的晶体。本文报道的方法产生均匀的Nb ₂ O ₅纳米棒，其平均直径为6 nm，长度为38 nm，其是通过水热工艺直接从铌酸合成的。在稳定纳米结构的表面活性剂存在下，研究了由铌酸形成的Nb ₂ O ₅纳米棒。结晶的Nb ₂ O ₅纳米棒的尺寸和形状相对均匀。Nb ₂ O ₅的大小即使没有蠕虫状的胶束形态，也可以通过选择表面活性剂来调节纳米棒。系统评估了胺，酰胺，铵，羧酸盐，磺酸盐和硫酸盐的表面活性剂对形成均匀Nb ₂ O ₅的能力的影响。纳米棒。本研究中的表面活性剂具有直链或支链的疏水尾部，例如聚合物，并包含一个或多个头基。纳米棒通过纳米颗粒的定向附着过程生长，该过程由添加到反应混合物中的表面活性剂调节。这些研究的结果表明，这种合成方法可作为可调谐平台，以制备具有明确定义的形态和尺寸的基于单晶氧化铌的纳米结构。这种表面活性剂辅助的结晶Nb ₂ O ₅纳米棒的形成也可能对其他基于过渡金属氧化物的纳米材料的设计产生重要影响。