V₂O₅-Fe₃O₄/rGO Ternary Nanocomposite with Dual Applications as a Dye Degradation Photocatalyst and OER...

The design and synthesis of structured nanomaterials with dual properties have always been highly attractive in various fields, especially in the reduction of environmental pollution as well as the generation of renewable energy. In this study, the synthesized ternary V₂O₅-Fe₃O₄/rGO nanocomposite was investigated to evaluate both the photocatalytic and electrocatalytic activities for the removal of methylene blue (MB) dye under UV/visible light radiation and oxygen evolution reaction (OER), respectively. The magnetized V₂O₅-Fe₃O₄/rGO nanocomposite is characterized by TEM, FE-SEM (with coupling by elemental mapping), EDS, XRD, FTIR, Raman, PL, DRS, and UV-vis analyses. The obtained results show that the graphene oxide substrate is decorated very well using Fe₃O₄ and V₂O₅ nanoparticles and converted to reduced graphene oxide (rGO). Furthermore, the V₂O₅-Fe₃O₄/rGO nanocomposite is considered as an active catalyst material to modify the commercial glassy carbon electrode for OER using linear sweep voltammetry (LSV). The photocatalytic activity of this novel nanocomposite revealed 89.2% (k_obs = 1.7 × 10^-2 min^-1) and 76% (k_obs = 8.3 × 10^-3 min^-1) degradation efficiencies of MB dye under UV and visible light irradiation at room temperature, respectively, and the surface area of the V₂O₅-Fe₃O₄/rGO nanocomposite was examined to be 705.8 cm²/g by N₂ adsorption-desorption isotherms. In addition, electrochemical measurements determined the best OER performance of the ternary nanocomposite with the lowest overpotential (458 mV) and Tafel slope (132 mV dec^-1) compared to the rGO substrate, Fe₃O_4, V₂O₅ nanoparticles, and binary nanocomposites. This work shows much enhancements in both photocatalytic and electrocatalytic activities due to the synergistic effect of the decorated GO support with V₂O₅ and Fe₃O₄ nanoparticles.