Impact of Annealing Treatment on the Green Synthesis of Magnetite (Fe<sub>3</sub>O<sub>4</sub>) Nanoparticles Using <i>Citrus limon</i> Juice for Antibacterial Activities

Magnetite nanoparticles are synthesized in an environmentally friendly way by utilizing natural ingredients found in citrus limon juice. The acid in citrus limon juice serves as a fuel for the sol-gel process, producing magnetite nanoparticles. Annealing treatment (400°C, 500°C, and 600°C) is used to change the structural and magnetic properties of the magnetite nanoparticles. All samples magnetite phase was verified by X-Ray Diffraction (XRD) examination. Increasing the annealing temperature causes an increase in crystallite size from 10.81 to 27.30 nm. Furthermore, the results of infrared spectroscopy revealed the presence of oxide bonds (M-O) in the range 558–567 cm -1 and 408–437 cm -1 , which are Fe-O bonds. Magnetic properties also change as a result of the annealing treatment, which is characterized by increased saturation magnetization and changes in other magnetic parameters. Furthermore, green synthesis of magnetite nanoparticles is effective against gram-negative bacteria ( E. Coli ) with enhanced antibacterial performance.