Influence factors of preparing carbon-encapsulated iron nanoparticles by gaseous detonation method

Abstract

Effects of molar ratio of hydrogen to oxygen and ferrocene mass on synthesis of carbon-encapsulated iron nanoparticles (Fe@C) were studied. Fe@C were prepared by using ferrocene as material resource, which decomposed by high temperature and high speed caused by hydrogen and oxygen detonation in homemade detonation tube. The samples were characterized by X-ray diffraction, transmission electron microscope and high resolution transmission electron microscope and it can be found that the molar ratio of hydrogen to oxygen, and ferrocene mass interact each other in the preparation of Fe@C. The molar ratio of hydrogen to oxygen mainly influences the morphology, particle size and dispersion of Fe@C, while ferrocene mass has a great affect on the synthesis of Fe@C. Part of iron element will be oxidized at small dosage of ferrocene, on the contrary, ferrocene couldn't be decomposed completely. When the molar ratio of hydrogen to oxygen is 2:1, ferrocene mass ranges in 2.5-3.5 g, spherical or ellipsoidal like Fe@C is prepared with a clear core-shell structure, and thickness of carbon shell at about 10 nm. In consideration of particle size uniformity, morphology structure and dispersion, the best condition for preparing Fe@C is, the molar ratio of hydrogen to oxygen at 2:1, ferrocene mass at 3.5 g.