Dye degradation property of cobalt and manganese doped iron oxide nanoparticles

Cobalt (Co) and manganese (Mn) doped iron oxide (Fe₃O₄) nanoparticles were synthesized using co-precipitation. Mn and Co (8 and 16%) were added gradually to Fe₃O₄ nanoparticles followed by annealing at 1000 °C. Co and Mn-doped Fe₃O₄ revealed cubic structure well matched to JCPDS # 01-089-2807 and 01-077-0426 respectively with crystallite size 8–21 nm confirmed by XRD. Mixing of Co and Mn improved absorption range toward longer wavelength as evident from UV–Vis spectroscopy. However, morphology of doped NPs was spherical and agglomerated visualized through field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM). Moreover, presence of metal–oxygen bond vibration in Co and Mn doped NPs was observed at 600 nm. On the other hand, saturation magnetization was highest for 16% Co-doped Fe₃O₄ attributed to excellent magnetic nature of cobalt nanoparticles. These findings showed superior performance of Co-doped magnetite compared to undoped and has been an interesting candidate to be used as nanocatalyst to replace conventional waste water management methods.