Synthesis an‎d Investigation of the Microstructure, Magnetic, an‎d Photocatalytic Properties of Cobalt Ferrite–Graphene Quantum Dot Composite

10/14/2026 12:00:00 AM

In this study, addressing the issue of pollutant removal from aquatic environments, a magnetic cobalt ferrite–graphene quantum dot composite was investigated through a photocatalytic mechanism. To enable degradation under visible light, biocompatible graphene quantum dots doped with nitrogen an‎d sulfur were incorporated into ferromagnetic cobalt ferrite particles. Cobalt ferrite was synthesized via the solvothermal method at 180 °C for 16 hours, while the graphene quantum dots an‎d the composite were synthesized using the hydrothermal method at 160 °C for 8 hours. The synthesized composite, along with cobalt ferrite an‎d graphene quantum dots, was characterized using X-ray diffraction (XRD), vibrating sample magnetometry (VSM), field emission scanning electron microscopy (FESEM), UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), photoluminescence spectroscopy (PL), diffuse reflectance spectroscopy (DRS), an‎d nitrogen adsorption–desorption analysis. Cobalt ferrite exhibited a saturation magnetization of 69 emu/g, while the composite showed 46 emu/g. The particles displayed a porous spherical morphology. DRS analysis revealed ban‎d gap energies of 3.7 eV for cobalt ferrite an‎d 3.3 eV for the composite. Pure cobalt ferrite showed an absorption edge at 300 nm (UV region), whereas co-doping with nitrogen an‎d sulfur extended light absorption into the visible region around 600 nm. Finally, in the methylene blue degradation test, the co-doped composite achieved a 70% degradation efficiency.

فريت كبالت , نقطه كوانتومي گرافن , تخريب متيلن بلو , سولوترمال

Cobalt ferrite , Graphene quantum dot , Methylene blue degradation , Solvothermal

Ali Ahmadi

dr. Seyed Mohammad Mirkazemi