程序升温反应法由纳米氧化铁制备纳米氮化铁

先以廉价的无机铁盐为主要原料,采用沉淀法和溶胶凝胶法制备纳米氧化铁粒子,由此得到粒径大小在10～20nm,20～40nm和40～60nm的氧化铁,在此基础上,以纳米氧化铁为前体,在氨气气氛下由程序升温反应法制备纳米氮化铁.研究发现,纳米氧化铁经程序升温反应氮化后,可以制备出纳米尺度的氮化铁.不同大小的氧化铁纳米粒子氮化后尺寸存在明显的差异,在一定范围内,小粒径的纳米氧化铁氮化后更容易长大;对于大小相近的γ相与α相纳米氧化铁粒子,γ氧化铁纳米粒子氮化后尺寸增大更为显著.制得的氮化铁的形貌与其氧化铁前体保持一致.

Preparation of Nano-iron Nitride by Temperature-programmed Reaction from Nano-iron Oxides

A series of nano-iron oxides with different particle sizes or bulk phases were firstly prepared from cheap inorganic iron salts by precipitation or sol-gel methods. Then, the nano-iron nitride samples were prepared from the as-synthesized nano-iron oxides by temperature-programmed reaction(TPR) method under ammonia atmosphere. The characterizations of X-ray diffraction and transmission electron microscope demonstrate that nano-iron nitride can be produced from the nano-iron oxides by TPR method. There are apparent differences in the particle sizes of iron nitride prepared from different precursors. Within some range of sizes, smaller iron oxide precursor leads to larger iron nitride particles. For the γ phase and α phase iron oxides with similar particle sizes, the former is more likely to agglomerate during the nitridation. The iron nitride particles retain the morphology of the oxide precursors.