TiO2/NiFe2-xCexO4/rGO ternary magnetic nanocomposite as separable and recyclable photocatalyst

This study investigates the synthesis and application of a TiO₂/NiFe_2-xCe_xO₄/rGO ternary magnetic nanocomposite as an efficient and recyclable photocatalyst. The nanocomposite was characterized using Fourier-transform infrared(FTIR), X-ray diffraction(XRD), Field emission scanning electron microscopy(FE-SEM), magnetic measurements, UV–Vis diffuse reflectance spectroscopy(DRS), and X-ray photoelectron spectroscopy (XPS). FTIR analysis confirmed the formation of the inverse spinel cubic structure, with significant vibrational bands related to metal–oxygen complexes. XRD patterns showed successful incorporation of Ce³⁺ ions into the NiFe₂O₄ lattice, with shifts in diffraction peaks indicating changes in crystallite size and lattice parameters. FE-SEM images revealed a well-dispersed distribution of TiO₂ and NiFe₂O₄ nanoparticles on the reduced graphene oxide (rGO) surface, enhancing the nanocomposite’s structural integrity. Energy dispersive X-ray(EDX) analysis demonstrated the presence of Ti, Ni, Fe, Ce, O, and C elements in the ternary nanocomposite without impurities, confirming the high purity of the material. Magnetic measurements indicated increased magnetization due to Ce³⁺ doping. DRS revealed optical band gaps (Bg), and XPS provided detailed insights into the surface chemical composition and valence states. XPS analysis confirmed the presence of Ni²⁺, Fe³⁺, Ti⁴⁺, and Ce³⁺ ions, and verified the reduction of graphene oxide to rGO. Importantly, the XPS data also indicated a reduction in the binding energy of oxygen species, which suggests effective electron trapping. The photocatalytic performance was assessed by the degradation of methylene blue (MB) under UV and Vis light. The TiO₂/NiFe_2-xCe_xO₄/rGO nanocomposite demonstrated superior photocatalytic activity with high degradation rates. The enhanced photocatalytic efficiency is attributed to efficient electron trapping, which reduces electron-hole recombination. Furthermore, the nanocomposite showed excellent reusability, maintaining high photocatalytic efficiency over multiple cycles of use, which underscores its potential for practical applications in environmental remediation.