气相爆轰合成碳包铁的影响因素

Influence Factors of Preparing Carbon-encapsulated Iron Nanoparticles by Gaseous Detonation Method

研究了氢氧摩尔比例与二茂铁质量对制备碳包覆铁纳米颗粒的影响。通过氢气与氧气爆轰产生的高温高速,在自制爆轰管内分解二茂铁,合成了碳包覆铁纳米颗粒。经XRD分析与TEM表征发现,氢氧比例与二茂铁质量在制备碳包铁时相互影响,氢氧比例主要影响碳包铁的形貌大小及分散性,二茂铁质量对能否合成碳包铁纳米颗粒影响很大。当氢氧比例为2：1,二茂铁质量在2.5~3.5 g时,能够合成碳包覆铁纳米颗粒,且呈球形或椭球形,具有明显的核壳结构。从颗粒大小均匀性,形貌结构及分散性考虑,氢氧比例2：1,二茂铁质量3.5 g的反应条件是制备碳包铁的较佳方案。

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.