Adhikari Menuka, Echeverria Elena, Risica Gabrielle, McIlroy David N, Nippe Michael, Vasquez Yolanda
Department of Chemistry, Oklahoma State University, 107 Physical Sciences I, Stillwater, Oklahoma 74078, United States.
Department of Physics, Oklahoma State University, 145 Physical Sciences II, Stillwater, Oklahoma 74078, United States.
ACS Omega. 2020 Aug 27;5(35):22440-22448. doi: 10.1021/acsomega.0c02928. eCollection 2020 Sep 8.
Nanowires and nanorods of magnetite (FeO) are of interest due to their varied biological applications but most importantly for their use as magnetic resonance imaging contrast agents. One-dimensional (1D) structures of magnetite, however, are more challenging to synthesize because the surface energy favors the formation of isotropic structures. Synthetic protocols can be dichotomous, producing either the 1D structure or the magnetite phase but not both. Here, superparamagnetic FeO nanorods were prepared in solution by the reduction of iron oxy-hydroxide (β-FeOOH) nanoneedles with hydrazine (NH). The amount of hydrazine and the reaction time affected the phase and morphology of the resulting iron oxide nanoparticles. One-dimensional nanostructures of FeO could be produced consistently from various aspect ratios of β-FeOOH nanoneedles, although the length of the template was not retained. FeO nanorods were characterized by transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, and SQUID magnetometry.
磁铁矿（Fe₃O₄）的纳米线和纳米棒因其多样的生物应用而备受关注，但最重要的是它们可用作磁共振成像造影剂。然而，磁铁矿的一维（1D）结构更具合成挑战性，因为表面能有利于各向同性结构的形成。合成方案可能是二分的，要么产生一维结构，要么产生磁铁矿相，但不能两者兼得。在这里，通过用肼（N₂H₄）还原氢氧化铁（β-FeOOH）纳米针在溶液中制备了超顺磁性Fe₃O₄纳米棒。肼的用量和反应时间影响了所得氧化铁纳米颗粒的相和形态。尽管模板的长度没有保留，但可以从β-FeOOH纳米针的各种纵横比一致地制备Fe₃O₄的一维纳米结构。通过透射电子显微镜、X射线粉末衍射、X射线光电子能谱和超导量子干涉仪磁力测量对Fe₃O₄纳米棒进行了表征。
