Assemblies of metal oxide nanowires in 3D stacks can enable the realization of nanodevices with tailored conductivity, porous structure and a high surface area. Current fabrication methods require complicated multistep procedures that involve the initial preparation of nanowires followed by manual assembly or transfer printing, and thus lack synthesis flexibility and controllability. Here we report a general synthetic orthogonal assembly approach to controllably construct 3D multilayer-crossed metal oxide nanowire arrays. Taking tungsten oxide semiconducting nanowires as an example, we show the spontaneous orthogonal packing of composite nanorods of poly(ethylene oxide)-block-polystyrene and silicotungstic acid; the following calcination gives rise to 3D cross-stacked nanowire arrays of Si-doped metastable ε-phase WO3. This nanowire stack framework was also tested as a gas detector for the selective sensing of acetone. By using other polyoxometallates, this fabrication method for woodpile-like 3D nanostructures can also be generalized to different doped metal oxide nanowires, which provides a way to manipulate their physical properties for various applications.

中文翻译：

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正交组装的3D交叉堆叠的金属氧化物半导体纳米线的合成。

3D堆栈中的金属氧化物纳米线组装可以实现具有定制的导电性，多孔结构和高表面积的纳米器件。当前的制造方法需要复杂的多步骤过程，该过程涉及纳米线的初始制备，然后是手工组装或转移印刷，因此缺乏合成的灵活性和可控性。在这里，我们报告了一种可控制地构建3D多层交叉金属氧化物纳米线阵列的通用合成正交组装方法。以氧化钨半导体纳米线为例，表明聚环氧乙烷-嵌段-聚苯乙烯和硅钨酸复合纳米棒的自发正交堆积。随后的煅烧产生了Si掺杂的亚稳态ε相WO3的3D交叉堆叠纳米线阵列。该纳米线堆栈框架也已作为气体检测仪进行了测试，以选择性地感测丙酮。通过使用其他多金属氧酸盐，这种类似木桩的3D纳米结构的制造方法也可以推广到不同的掺杂金属氧化物纳米线，从而为各种应用提供了一种控制其物理性能的方式。