Synthesis of superparamagnetic iron oxide nanoparticles in carbon reduction method

Owing to the superparamagnetic iron oxide nanoparticles´ wide applications, a new approach in the synthesis of mainly superparamagnetic iron oxide nanoparticles is reported. The Fe₃O₄ nanoparticles (~500 nm) were synthesised through the carbon reduction method, which is a brand new method. The best parameters of synthesis of the nanoparticles are fixed through characterising by transmission electron microscope (TEM), X-ray diffraction and a vibrating sample magnetometer of the Fe₃O₄ nanoparticles obtained under different experimental conditions. The TEM characterisation results show that the best ratio of the carbon and ferric chloride is 3:1 and the most suitable heating time is 3 h. The nanoparticles, which were obtained with furnace cooling under vacuum condition after 3 h heating, have the best magnetic properties and most stable crystal from. The characterisations of SiO₂ protected nanoparticles demonstrate that the component of the nanoparticles is Fe₃O₄. The UV-vis absorption spectrum of the Fe₃O₄ nanoparticles demonstrates wide-range light absorption of the Fe₃O₄ nanoparticles. Moreover, quantitative analysis of this new method is conducted to confirm repeatability. The actual qualities of the Fe₃O₄ nanoparticles are always consistent with the theoretical ones, which indicate that the repeatability of this method is excellent.