Enhanced photocatalytic activity of V₃O₇ / V₂O₅ – reduced graphene oxide nanocomposite towards methylene blue dye degradation

This work investigates the photocatalytic performance of V₂O₅ and V₃O₇ nanoparticles and their nanocomposites with rGO. The as-annealed V₂O₅ and V₃O₇ nanoparticles exhibited pure orthorhombic and monoclinic structures with an optical bandgap of 2.3 and 2.5 eV, respectively. The corresponding vibrational modes using Raman and FTIR spectroscopy analysis further confirm the form. The morphological studies reveal that V₂O₅ and V₃O₇ nanoparticles possess plate and petal-like morphology, respectively. Moreover, in the case of V₂O₅/V₃O₇—rGO nanocomposites, the plate/petal-like nanoparticles are embedded within rGO sheets. Incorporating nanoparticles within rGO sheets has quenched the green photoluminescence emission, enhancing their photocatalytic performance upon irradiation with white light of 100 mW/cm². This is ascribed to the effective transport of interfacial electrons from vanadium oxide nanoparticles to the rGO surface, reducing the recombination of photogenerated charge carriers. These results indicate that the vanadium oxide/rGO nanocomposites have potential applications in wastewater treatment.