Department of Chemical and Materials Engineering, Chang Gung University, Guishan, Taoyuan 33302, Taiwan.
Department of Chemical Engineering and Materials Science, Yuan Ze University, Chung-Li, 32003, Taiwan.
J Nanosci Nanotechnol. 2019 Dec 1;19(12):7645-7653. doi: 10.1166/jnn.2019.16846.
This study synthesizes iron(III) oxide magnetic nanoparticles (MNPs) using a facile and eco-friendly microwave-assisted solvothermal method. The highly porous particles become stable after a 60-min reaction when the temperature is fixed at 200 °C, in which the particle size is kept at 100-150 nm. The magnetic properties, crystal structure, surface morphology, and microstructures of the prepared MNPs are then analyzed. The microstructure analysis suggests that a MNP consists of numerous small Fe₃O₄ particles with a size smaller than 10 nm; therefore, a large amount of microcracks is observed between grains. Moreover, the orientations in these particles are very close, implying that they grow toward the same direction that may be provided by the nuclei. The prepared MNPs thus possess a highly porous structure and have a 3-times larger specific surface area than the commercially-available MNPs. Finally, the growth mechanism of iron(III) oxide MNPs by the present process is proposed.
本研究使用简便、环保的微波辅助溶剂热法合成了三氧化二铁磁性纳米颗粒（MNPs）。当温度固定在 200°C 时，反应 60 分钟后，高度多孔的颗粒变得稳定，颗粒尺寸保持在 100-150nm 之间。然后分析了所制备的 MNPs 的磁性能、晶体结构、表面形态和微观结构。微观结构分析表明，一个 MNPs 由许多小于 10nm 的 Fe₃O₄ 小颗粒组成，因此在晶粒之间观察到大量微裂纹。此外，这些颗粒中的取向非常接近，这意味着它们朝着可能由核提供的相同方向生长。因此，所制备的 MNPs 具有高度多孔的结构，比市售的 MNPs 具有大 3 倍的比表面积。最后，提出了本工艺制备三氧化二铁 MNPs 的生长机制。
