Abstract

The properties and structure of magnetic graphene oxide GrO/iron oxide FeOx nanocomposites synthesized by the mechanochemical method with different content of components GrO : FeOx (wt %), namely, 20 : 80, 50 : 50, and 80 : 20 were studied. The method of mechanochemical synthesis is a mechanical process of grinding iron oxide powder together with graphene oxide in a ball mill in an aqueous medium. The synthesized magnetic GrO/FeOx nanocomposites were studied by Raman spectroscopy, a vibrating sample magnetometer, and Mössbauer spectroscopy. The Mössbauer studies made it possible to determine the phase composition and structure of the synthesized magnetic GrO/FeOx nanocomposites. The data of Mössbauer spectroscopy showed that the GrO/FeOx composites consist of the magnetite phase Fe₃O₄ and magnetic nanoparticles in the paramagnetic state, which is consistent with the data of X-ray diffraction studies. Based on the results of Mössbauer spectroscopy, it was found that, in addition to magnetite, the magnetic GrO/FeOx nanocomposites contain hematite α-Fe₂O₃, as well as phases identified as iron carbides and iron-depleted carbon clusters. The latter were not detected by X-ray diffraction, apparently because their number is insignificant and they are in an amorphous state. The results obtained show that graphene is not just a source of carbon during grinding in a ball mill, but has its own reactivity and the ability to generate new phases during mechanochemical activation. Based on the performed Mössbauer spectral studies, we obtained unique and important information on the magnetic structure of the magnetic GrO/FeOx nanocomposites. The research results make it possible to explain the magnetic properties of magnetic nanocomposites, GrO/magnetic particles, which is important for the development and graphene oxide-based synthesis of high-performance magnetic nanocomposites for various applications, including biomedicine.

中文翻译：

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用于生物医学的氧化石墨烯/氧化铁 (GrO/FeOx) 纳米复合材料：合成与研究

摘要

研究了通过机械化学方法合成的磁性氧化石墨烯 GrO/氧化铁 FeOx 纳米复合材料的性能和结构，其中 GrO:FeOx 的组分含量 (wt%)，即 20:80、50:50 和 80:20。机械化学合成方法是在水介质中在球磨机中将氧化铁粉末与氧化石墨烯一起研磨的机械过程。通过拉曼光谱、振动样品磁强计和穆斯堡尔光谱研究合成的磁性 GrO/FeOx 纳米复合材料。穆斯堡尔研究使确定合成磁性 GrO/FeOx 纳米复合材料的相组成和结构成为可能。穆斯堡尔谱数据表明 GrO/FeOx 复合材料由磁铁矿相 Fe ₃ O _{4 组成}和处于顺磁性状态的磁性纳米粒子，这与 X 射线衍射研究的数据一致。根据穆斯堡尔谱的结果发现，磁性GrO/FeOx纳米复合材料中除磁铁矿外还含有赤铁矿α-Fe ₂ O ₃，以及鉴定为碳化铁和贫铁碳簇的相。后者没有被 X 射线衍射检测到，显然是因为它们的数量微不足道，而且它们处于无定形状态。获得的结果表明，石墨烯不仅是球磨机研磨过程中的碳源，而且在机械化学活化过程中具有其自身的反应性和生成新相的能力。基于进行的穆斯堡尔光谱研究，我们获得了关于磁性 GrO/FeOx 纳米复合材料的磁性结构的独特而重要的信息。研究结果使得解释磁性纳米复合材料 GrO/磁性颗粒的磁性成为可能，这对于开发和基于氧化石墨烯合成各种应用的高性能磁性纳米复合材料具有重要意义，