The morphology-dependent on the electrochemical performance of molybdenum trioxide in supercapacitors

The energy storage performance of transition metal oxides (TMO) as electrode materials for supercapacitors exhibit a strongly morphology-dependent due to changes in the local electronic and microscopic geometric structure of the interface. Herein, MoO₃ with morphology in nanoprisms (NP), nanostrips (NS), and nanobulks (NB) were prepared by different synthesis routes. The morphology and structural characteristics of the three obtained MoO₃ were characterized by scanning electron microscopy, the high resolution transmission electron microscopy, Brunauer–Emmett–Teller techniques, X-ray diffraction, and X-ray photoelectron spectroscopy. And then, the significant effects of the morphologies of MoO₃ on the electrochemical activity were assessed using cyclic voltammetry and galvanostatic charge-discharge measurements. The supercapacitors using MoO₃-NP as electrode achieved the largest specific capacitance of 254.0 F g⁻¹ at a current density of 0.3 A g⁻¹ as compared to 123.3 F g⁻¹ of MoO₃-NS, and 8.7 F g⁻¹ of MoO₃-NB in 1 mol L⁻¹ Na₂SO₄ electrolyte. Among them, the MoO₃-NP electrode has the highest pseudo-supercapacitive response and excellent cycling stability than the other electrodes, which is attributed to the morphology-dependent to enhance the electrical conductivity and promote the generation of active reaction sites. Therefore, the MoO₃-NP electrode can be significantly applied to supercapacitors for cost reduction and energy conversion efficiency improvement.