Synthesis, characterization, and photocatalytic potential of CoFe₂O₄ nanoparticles immobilized on graphitic carbon nitride

The CoFe₂O₄/g-C₃N₄ (CF/GCN) heterojunction was successfully synthesized by a sol–gel auto-combustion method. In synthesis, cow urine was used as a stabilizing and chelating agent. Further, the synthesized CoFe₂O₄ (CF), g-C₃N₄ (GCN), and CF/GCN heterojunctions were characterized utilizing X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV–visible diffuse reflectance spectroscopy (DRS) techniques. The findings show that the heterojunction is composed of spherical cobalt ferrite nanoparticles attached to the graphitic carbon nitride nanosheets. The synthesized photocatalysts' optical characteristics were examined, and the findings demonstrated that the heterojunction between CF and GCN enhanced light absorption, decreased the band gap, and separated the e⁻/h⁺ pairs. Photocatalytic efficacy of the CF/GCN was assessed by degrading of methylene blue (MB) and methyl orange (MO) under visible light irradiation. The photocatalytic efficacy of the CF15/GCN photocatalyst was higher than pure CF and GCN nanoparticles. Under stimulated visible light, it decomposed MB up to 93.61% and MO up to 88.42% in 90 min, which is greater than that of pure CF (49.71%; 44.12%) and GCN (37.14%; 31.21%). This substantial improvement can be attributed to synergistically enhanced electron/hole pair separation in CF15/GCN heterojunction. Also, the possible degradation mechanism has been proposed according to experimental results.