Phase Transition Of MoO₃ Nanobelts Under External Fields

As an ideal electrode material,molybdenum oxide?MoO₃?nanomaterials have been widely studied by transmission electron microscopy.In addition,MoO₃ has an important role in the molybdenum steel and the oxidation of hydrocarbons industry.However,MoO₃ is prone to phase transition under electron beam irradiation and high temperature environment,so it is necessary to study the phase transition under these two kinds of external fields.In this paper,MoO₃ nanobelts with orthogonal structure were synthesized by an improved hydrothermal method.The influences of electron beam irradiation and temperature on the phase transition of the MoO₃ nanobelts were studied by transmission electron microscopy.The results show that MoO?a = b = c = 0.408 nm?with face-centered cubic structure was obtained from MoO₃ by electron beam irradiation,and the orientation relationship between the two phases is:[010]MoO₃//[010]MoO,?200?MoO₃//?200?MoO.The effect of temperature on the structure of MoO₃ nanobelts was studied by in situ heating samples holder.The results indicated that:MoO₃ transform to monoclinic MoO2 phase?a = 0.566 nm,b=0.486 nm,c =0.565 nm,? = 120.94°?at 873 K.Nanoparticles with twinning plane of?011?were found in the product.The results of this study provide reference for in situ investigations of charge/discharge mechanism and the reduction mechanisms of catalysts at atomic scale.At the same time,the relationship between electron beam irradiation effect and heating effect is further explored.