Controllable synthesis and formation mechanism of pure and Fe-doped h-MoO3 microrods under hydrothermal reaction conditions

In the present work, pure and Fe-doped h-MoO3 microrods were successfully synthesized via the hydrothermal method using (NH4)(6)Mo7O24 & BULL;4H(2)O and concentrated HNO3 as the raw materials. Various technologies, such as XRD, FESEM-EDS, TEM, and SAED pattern, were adopted to characterize the resulting products. The result showed that the optimum conditions for the controllable synthesis of pure h-MoO3 microrods were 150 & DEG;C, 16 h, and with a solid-liquid ratio of 1 : 2. Due to the similar ionic radius of Fe3+ and Mo6+, it was discovered that adding a small amount of Fe dopant (1-5 mass%) would not lead to an obvious change in the lattice parameters; however, the particle size of the as-synthesized Fe-doped h-MoO3 would be increased gradually. Also, the photocatalytic performances of the Fe-doped h-MoO3 increased first and then decreased with increasing the amount of Fe dopant. NH4+ and OH- existing in the system played crucial roles on the formation of h-MoO3 microrods, likely by acting as structure-directing and stabilizing agents for h-MoO3 crystalline. In addition, it was found that the transformation process from h-MoO3 microrods to & alpha;-MoO3 nanofibers obeyed the dissolution-recrystallization mechanism.

Automated summary

In this study, pure and Fe-doped h-MoO3 microrods were successfully synthesized via the hydrothermal method. Different characterization techniques were used to analyze the resulting products. The addition of Fe dopant did not significantly change the lattice parameters of h-MoO3, but increased the particle size. The photocatalytic performance of Fe-doped h-MoO3 first increased and then decreased with increasing amount of Fe dopant. NH4+ and OH- played important roles in the formation of h-MoO3 microrods.