Magnetic Fe3O4@V2O5/rGO nanocomposite as a recyclable photocatalyst for dye molecules degradation under direct sunlight irradiation.

Reduced graphene oxide nanosheets decorated with Fe3O4 and V2O5 nanoparticles as a magnetically recoverable nanocomposite (Fe3O4@V2O5/rGO) was synthesized by a simple solution chemistry approach. The synthesized nanocomposite was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier transform infrared (FTIR), fluorescence, and zeta potential measurements. The narrow band gap and different band gap energies of Fe3O4 and V2O5 proved to be suitable for the absorption of visible light in the solar spectrum. The Fe3O4@V2O5/rGO displayed indeed excellent photocatalytic activity towards the degradation of harmful cationic Bismarck Brown (BB) as well as anionic Acid Orange 7 (AO) dyes under direct sunlight irradiation. The photocatalytic activity of the Fe3O4@V2O5/rGO is influenced by solution pH, catalyst loading, initial dye concentration and the presence of different inorganic ions (NH4+, Na+, Mg2+, Ca2+, SO42-, Br-, NO3-, Cl-, HCO3-). This study provides a new scientific knowledge on the sunlight driven photocatalytic degradation of dye molecules using novel mixed metal oxide/rGO nanocomposite photocatalyst.