Role of tetravalent Ti4+ doping on the photocatalytic application of cobalt ferrite nanoparticles

The current study examines the preparation and characteristics of dye degradation studies under sunlight using cobalt ferrite photocatalysis. The samples were prepared by the glycine-assisted sol-gel self-combustion method. XRD analysis was performed to prove the single-phase formation with a cubic spinel structure. The Scherrer equation was employed to obtain the crystalline size, which ranged between 12 nm and 16 nm. The unit cell parameter (a) was evaluated using the XRD data, which showed a decreasing trend with Ti⁴⁺ doping. The other structural parameters also showed a strong influence of Ti⁴⁺ doping. Two absorption bands are visible in the FT-IR spectra close to 400 cm^‐−1 to 600 cm⁻¹, which increase with Ti⁴⁺ doping. Surface analysis by FE-SEM suggested a spherical morphology with a grain size of approximately 25 nm. EDX spectrum analysis proved the stoichiometry proportion of each element. The spinel structure is identified in Raman spectroscopy by five active vibrational modes (3T_2g + E_g + A_1g). The surface area obtained from BET analysis varies between 5.74 to 17.52 (m²/g) for typical samples. Optical characterization was performed using UV–Visible spectroscopy. The Tauc plot's direct band gap ranges from 1.85 eV to 2.29 eV. The degradation of Methylene Blue (MB) dye in the presence of sunshine was used to assess the photocatalytic activity. Thus, it was found that the optimal photocatalyst arrangement was Co_1.10Fe_1.8Ti_0.10O₄, which showed a maximum degradation efficiency of 87.81 % after 140 min.