Modified monoclinic metastable β-MoO3 submicrospheres: controllable preparation, phase identification, and their formation mechanisms

作者：Wang, Lu^*; Zhang, Guo-Hua

来源：Ceramics International, 2023, 49(11): 18756-18769.

DOI：10.1016/j.ceramint.2023.02.254

• beta-MoO3
• Controllable preparation
• Submicrospheres
• Formation mechanism

In this work, a modified monoclinic metastable beta-MoO3 (identified as N-doped beta-MoO3-theta) submicrospheres (SMSs) were prepared by the method of sublimation with using industrial MoO3 as the raw material in the range of 1173-1373 K. Various technologies such as XRD, SEM, FE-SEM, TEM, Raman, and XPS spectra were adopted to characterize the as-prepared product. The result showed that the phase composition of the as-prepared product had no obvious relationship with the reaction temperature and cooling condition, while the pumping speed of the system exerted important roles on it. When the pumping speeds were low (4 and 15 cm/s), uniform N-doped beta-MoO3-theta SMSs were prepared; increasing the pumping speeds to 20 cm/s or higher, both N-doped beta-MoO3-theta SMSs and alpha-MoO3 nanoplates (NPs) were appeared. Optimum conditions for the controllable preparation of N-doped beta-MoO3-theta SMSs were recognized as 1273 K, water cooling, and with a pumping speed of 4-15 cm/s. The growth mechanism of large MoO3 spherical-shaped particles were due to the collision and gases deposition effects. This work also discovered that the cracking phenomena were often occurred on the surface of large MoO3 particles obtained under the air cooling and high pumping speed conditions, and the possible cracking mechanisms were illustrated.

• 单位
  北京科技大学