MoO3纳米纤维的制备及其氢还原特性研究

Preparation and Hydrogen Reduction Property of MoO3 Nanofibers

摘要:

以仲钼酸铵和硝酸为原料通过水热法在170 ℃下恒温40 h获得直径为50~100 nm、长度大于20 μm的MoO3纳米纤维。在450~650 ℃的不同温度下对所合成的MoO3纳米纤维进行氢气还原，利用XRD和FSEM对还原样品进行表征。结果发现，MoO3纳米纤维在450 ℃的还原温度下有MoO2形成，在600 ℃的温度下被完全还原成粒度为0.1~2 μm的Mo粉。在还原过程中，大部分MoO3纳米纤维形状不具有继承性，而处于自由空间的小部分单根MoO3纳米纤维可以转化成针状Mo颗粒。

关键词:MoO3纳米纤维;水热合成;氢气还原

Abstract:

MoO3 nanofibers with 50~100 nm diameter and larger than 20 μm length were prepared at 170 ℃ constant temperature for 40 h using (NH4)6Mo7O24·4H2O and nitric acid as starting materials through hydrothermal process. Then the hydrogen reduction tests of the prepared MoO3 nanofiber were carried out at different temperatures within 450~650 ℃. The samples prepared by hydrogen reduction tests were characterized by XRD and FSEM. The results indicated that MoO3 nanofibers began to change into MoO2 at 450 ℃, and could be completely reduced to Mo powder with 0.1~2 μm particle size at 600 ℃. During the reduction process, the original fiber-like morphology of most MoO3 nanofibers was not well-retained; but in some cases, the fiber-like morphology of a small part of single MoO3 nanofibers in free space could be retained, and changed into needle-like Mo particles.

Key words:MoO3 nano-fiber; hydrothermal synthesis; hydrogen reduction