Nano MoO3 Phase Structural Evolution During Hydrothermal Synthesis and Its Electrochemical Properties

Micron rods of hexagonal MoO 3 (h-MoO 3 ) and nanobelts of orthorhombic MoO 3 (α-MoO 3 ) were prepared using a facile hydrothermal synthesis. The factors that influenced the morphologies, crystalline structures and electrochemical properties of the MoO 3 were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental revealed that both the reaction time and acidity coefficient played important roles in controlling the crystalline structure and morphology of the MoO 3 ; however, the acidity coefficient was the crucial factor. At lower acidity coefficient, the growth of the MoO 3 nucleus only resulted in well-crystallized h-MoO 3 rods as the reaction time increased. As the acidity coefficient increased, the h-MoO 3 phase was transformed into an α-MoO 3 phase and the morphology changed gradually from three-dimensional hexagonal micron rods to low-dimension nanobelts. As the anode electrode, the α-MoO 3 nanobelts exhibited better electrochemical properties. The initial specific capacities of 223.1 mAh•g -1 and a wide discharge plateau of 2.2V for the α-MoO 3 were obtained. On the other hand a stable electrochemical performance was achieved for h-MoO 3 micron rods.