Enhanced electrochemical properties of V2O5 and g-C3N4- V2O5 nanocomposites for rechargeable battery systems

Abstract

Nanostructured V₂O₅ (nanorods and nanoplatelets) and g-C₃N₄-V₂O₅ nanocomposite were synthesized via thermal condensation method and characterized using X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), UV–Visible diffuse reflectance spectroscopy (UV–Vis-DRS), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM). XRD analysis confirmed the phase purity of the samples, while IR and UV–Vis spectroscopy revealed the presence of pure V₂O₅ without impurities. The band gap of the V₂O₅ nanostructures was calculated to be approximately 2.0 eV from the optical absorption edge. SEM and TEM analysis revealed particle sizes ranging from 15 to 35 nm, with higher concentrations of oxalic acid yielding smaller particles. The quantity of oxalic acid was found to significantly influence the final morphology of the nanostructures. Electrochemical studies revealed good mobility and reversibility of cation, with reduced resistance and enhanced charge transfer kinetics in the g-C₃N₄-V₂O₅ nanocomposite. The nanocomposite exhibited a high discharge capacity of 320 mAh/g and a capacity retention of 85 % after 100 cycles. Impedance studies further revealed reduced resistance in the nanocomposite materials, indicating enhanced charge transfer kinetics. The synthesized V₂O₅ nanorods, nanoplatelets, and g-C₃N₄-V₂O₅ nanocomposite show promise as cathode materials for magnesium ion rechargeable batteries.