Key Laboratory of Industrial Internet of Things & Networked Control, Ministry of Education, School of Automation, Chongqing University of Posts and Telecommunications, Chongqing 400065, People's Republic of China.
Nanotechnology. 2020 Apr 3;31(14):145601. doi: 10.1088/1361-6528/ab622f. Epub 2019 Dec 16.
High-performance iron nanowires have attracted wide attention from researchers due to their 'controllable' arrangement distribution by magnetic fields. In this paper, a simple magnetic field assisted in situ reduction method was proposed to synthesize Fe NWs with high aspect ratio, small-diameter, and good dispersion. A detailed parametric study determining the relationship among the final morphologies of the products and magnetic field, injection sequence of sodium borohydride that was injected into ferrous sulfate heptahydrate, reactant concentration, and injection rate is presented. The as-synthesized Fe NWs were analyzed by scanning electron microscopy, transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy and vibrating sample magnetometry. A plausible mechanism for the formation of high-aspect-ratio Fe NWs is proposed. The SEM images showed the dependence of the NWs morphology and aspect ratio on synthesis parameters. Magnetic field and injection sequence showed considerable influences on the synthesis of high-aspect-ratio Fe NWs. In the absence of magnetic field or with the changes in injection sequence, only the Fe flakes were obtained. The NWs diameter decreased, and the aspect ratio increased with the increase in injection rate. The FeSO·7HO and NaBH concentration considerably influenced the aspect ratio of the product, which increased first, decreased, and then increased again with the increase in FeSO·7HO concentration. Meanwhile, the product aspect ratio increased and then became saturated with the increase in NaBH concentration Thus, an optimum synthesis process was obtained, with the average aspect ratio of 350, and the average diameter of 60 nm. The results reported in this paper provide a basis for optimizing the growth of Fe NWs by magnetic field-assisted method.
高性能铁纳米线因其可通过磁场“控制”排列分布而引起了研究人员的广泛关注。在本文中，提出了一种简单的磁场辅助原位还原方法，用于合成具有高纵横比、小直径和良好分散性的 FeNWs。详细的参数研究确定了产物最终形态与磁场、注入七水合硫酸亚铁的硼氢化钠的注入顺序、反应物浓度和注入速率之间的关系。通过扫描电子显微镜、透射电子显微镜、X 射线衍射、X 射线光电子能谱和振动样品磁强计对合成的 FeNWs 进行了分析。提出了一种形成高纵横比 FeNWs 的合理机制。SEM 图像显示了 NWs 形态和纵横比对合成参数的依赖性。磁场和注入顺序对高纵横比 FeNWs 的合成有很大的影响。在没有磁场或改变注入顺序的情况下，只能得到 Fe 薄片。随着注入速率的增加，NWs 直径减小，纵横比增加。FeSO·7HO 和 NaBH 的浓度对产物的纵横比有很大的影响，随着 FeSO·7HO 浓度的增加，纵横比先增加，然后减小，然后再次增加。同时，随着 NaBH 浓度的增加，产物的纵横比增加并达到饱和。因此，获得了最佳的合成工艺，平均纵横比为 350，平均直径为 60nm。本文的研究结果为通过磁场辅助方法优化 FeNWs 的生长提供了依据。
