MoO₃/WO₃/rGO as electrode material for supercapacitor and catalyst for methanol and ethanol electrooxidation

The potential of metal oxides in electrochemical energy storage encouraged our research team to synthesize molybdenum oxide/tungsten oxide nanocomposites (MoO₃/WO₃) and their hybrid with reduced graphene oxide (rGO), in the form of MoO₃/WO₃/rGO as a substrate with relatively good electrical conductivity and suitable electrochemical active surface. In this context, we presented the electrochemical behavior of these nanocomposites as an electrode for supercapacitors and as a catalyst in the oxidation process of methanol/ethanol. Our engineered samples were characterized by X-ray diffraction pattern and scanning electron microscopy. As a result, MoO₃/WO₃ and MoO₃/WO₃/rGO indicated specific capacitances of 452 and 583 F/g and stability of 88.9% and 92.6% after 2000 consecutive GCD cycles, respectively. Also, MoO₃/WO₃ and MoO₃/WO₃/rGO nanocatalysts showed oxidation current densities of 117 and 170 mA/cm² at scan rate of 50 mV/s, and stability of 71 and 89%, respectively in chronoamperometry analysis, in the MOR process. Interestingly, in the ethanol oxidation process, corresponding oxidation current densities of 42 and 106 mA/cm² and stability values of 70 and 82% were achieved. MoO₃/WO₃ and MoO₃/WO₃/rGO can be attractive options paving the way for prospective alcohol-based fuel cells.