Microstructural study of sonochemical synthesized belt-like Zr(MoO₄)₂/MoO₃ composites for efficient energy storage

It is currently being widely explored as an electrode material for future storage devices that transition metal oxides can provide a synergistic effect during electrochemical reactions. We synthesized composites of Zr(MoO₄)₂/MoO₃ with belt-like morphologies using ligand assisted Ultrasonics. Compared to other methods of synthesis, ultrasonic synthesis is less costly and easier to use, and it has the advantage of speeding up the formation process. It is possible that the duration of the sonication process can have an impact on the microstructural properties of the sample. As a result, Zr(MoO₄)₂/MoO₃ composites were synthesized under ultrasonic probes for five, ten, and fifteen minutes, respectively. The achieved sample serves as an active material in an electrochemical energy storage system comprised of a three-electrode cell and an electrolyte containing KOH. Depending on the current density, the kinetics of the electrochemical reaction and the stability of the materials in the working electrode are affected. Nevertheless, the capacity of Zr(MoO₄)₂/MoO₃ composites was studied at different currents of 0.5, 1, 2 and 3 mA in order to identify optimal parameters. The results indicate an increase in discharge capacity at 2 mA from the first cycle to the thirteenth cycle, from 200 to 750 mAhg⁻¹. In contrast, applying a current of 3 mA results in a decrease in capacity and structural damage. Conversely, using lower currents of 0.5 and 1 mA results in lower capacity compared to 2 mA. In this way, belt-like Zr(MoO₄)₂/MoO₃ composites can be utilized as potential active materials in energy storage systems, such as hydrogen storage.