Graphene/Bismuth-Codoped Fe3O4 Nanocomposites for UV Light-Assisted Photodegradation of Industrial Dyes Produced by the Coprecipitation Method

Abstract

Industrial dye waste is extremely poisonous, nonbiodegradable, and has a severe detrimental effect on the ecosystem. Graphene-doped Fe₃O₄ nanocomposites (G/F-NCs), undoped Fe₃O₄ nanoparticles (F-NPs), bismuth-doped Fe₃O₄ nanoparticles (Bi/F-NPs) and graphene-bismuth codoped Fe₃O₄ nanocomposites (G/Bi/F-NCs) all successfully photodegrade phenothiazine derivative dyes. The face-centered cubic structure of metallic Fe₃O₄ is confirmed by the X-ray powder diffraction patterns of all the produced samples. The rise in crystallite size in the Bi-doped samples shows that the addition of Bi 4f considerably accelerates the formation of crystalline grains in Fe₃O₄, whereas the addition of graphene dopants causes a decrease in particle size and an expansion of the bandgap. The addition of graphene nanoflakes and the development of secondary pores are credited with giving G/Bi/F-NCs (90.847m²/g) a larger specific surface area. The presence of oxygen anion, graphene, Bi 4f ion and Fe 3p and Fe 2p oxidation states in the Fe₃O₄ lattice is confirmed by the X-ray photoelectron spectra of O 1s, C1s, Bi 4f and Fe 2p.