Synthesis of polyoxometalates, copper molybdate (Cu3Mo2O9) nanopowders, for energy storage applications

Synthesis of polyoxometalates (Cu3Mo2O9 nanopowders) was obtained by using solvothermal method and confirmed by X-ray diffraction pattern, with orthorhombic crystalline structure belonging to the space group Pna2(1)(33). Further, the synthesized Cu3Mo2O9 nanopowders were analyzed by using Raman, infrared, and photoluminescence studies. X-ray photoelectron spectroscopy study explained the oxidation states of Mo-3d, Cu-2p, and O-1s in Cu3Mo2O9 nanopowders. Field emission scanning electron microscopy images clearly revealed the formation of nanostructure randomly oriented to form an interconnected rout, which emerged as a good candidate for storing more charges at the surface of Cu3Mo2O9 nanopowders. The electrochemical studies, such as cyclic voltammetry, electro impedance analysis, and galvanostatic charging-discharging studies, were used to analyze its electrochemical properties. To ensure the stability of Cu3Mo2O9 nanopowders, continuous charging and discharging studies were conducted for 1000 cycles at a current density of 5Ag(-1) and it exhibited good stability over a large number of cyclic studies with capacity retention of 99.2% after the first 500 cycles.