Improving the Thermal Expansion and Capacitance Properties of MoO3 by Introducing Oxygen Vacancies

Oxygen vacancies have a profound effect on the electric, magnetic, and optical properties of transition-metal oxides, but their effect on thermal expansion properties has rarely been studied. Herein, we report the effect of oxygen vacancies on the thermal expansion properties and capacitance of MoO3. It is found that the introduction of oxygen vacancies significantly reduces the orthorhombic strain and thermal expansion anisotropy and results in the decrease of the coefficient of thermal expansion by about 30%. Furthermore, the capacitance of MoO3 can be enhanced by about 323%, which is associated with the increase of layer spacing as well as the increase of conductivity. Reducing the thermal expansion coefficient and enhancing the capacitance of MoO3 by introducing oxygen vacancies could provide an effective strategy for improving the device performance of related materials, such as supercapacitors.