Design of α-CoMoO4 Nanoflakes on Carbon Cloth and Investigation of Their Pseudocapacitance in Non-Aqueous Electrolyte and Electro-Oxidation of Methanol

Nanocrystalline cobalt molybdate (CoMoO₄) nanoflakes were grown directly on carbon fiber cloth (CFC) via a simple hydrothermal method without any template or surfactant. Structure and morphology of the sample was characterized by x-ray diffraction (XRD), Raman spectra, scanning electron microscope (SEM), and transmission electron microscope (TEM). A symmetric supercapacitor was fabricated using nanocrystalline CoMoO₄ nanoflakes as both negative and positive electrodes. The device has delivered a maximum specific capacitance of 8.3 F/g at a constant current density of 1 A/g in organic electrolyte. It offers a reasonable energy (2.6 Wh/kg) and power (748.8 W/kg) density as comparable to the carbon based symmetric supercapacitors. As a catalyst for methanol oxidation, the CoMoO₄ nanoflakes showed high current density (25 mA/cm²) and low onset potential (0.38 V). The impressive bi-functional electrochemical activity of CoMoO₄ on CFC mainly attributed to their porous microstructure, reasonable electrical conductivity resulted from binder-free and intimate metal oxide/substrate integration.