UV Light‐Assisted Photodegradation of Industrial Dyes by Reduced Graphene Oxide/Nickel Codoped Fe3O4 Nanocomposites Synthesized Using the Coprecipitation Method

Abstract

Industrial dye waste is highly toxic, nonbiodegradable, and has a significant negative impact on the environment. Photodegradation of phenothiazine derivative dyes by undoped Fe3O4 nanoparticles (Fe3O4), reduced graphene oxide (rGO)‐doped Fe3O4 nanocomposites (G@Fe3O4), nickel‐doped Fe3O4 nanoparticles (Ni@Fe3O4), and graphene–nickel codoped Fe3O4 nanocomposites (Ni/G@Fe3O4) is achieved using a facile coprecipitation technique. The X‐ray powder diffraction patterns of all the prepared samples confirm the face‐centered cubic structure of metallic Fe3O4. The crystallite size of the Ni‐doped samples increases, indicating that the addition of Ni2+ significantly increases the crystalline grain growth of Fe3O4, whereas the addition of graphene dopants results in a decrease in the particle size and an increase in the bandgap. The higher specific surface area of Ni/G@Fe3O4 (70.082 m2 g−1) is attributed to the introduction of rGO nanoflakes and the formation of secondary pores. The X‐ray photoelectron spectra of O 1s, C 1s, Ni 2p, and Fe 2p confirm the presence of oxygen anions, graphene, Ni2+ ions, and Fe3+ and Fe2+ oxidation states in the Fe3O4 lattice.