Green synthesis of Fe3O4/Ag composite nanoparticles using Moringa oleifera: Exploring microstructure, optical, and magnetic properties for magnetic hyperthermia applications

This study investigates the green synthesis of Fe3O4/Ag composite nanoparticles using Moringa Oleifera (MO) extract in the coprecipitation process. The microstructure, optical, and magnetic properties of the synthesized nanoparticles are examined and the specific absorption rate (SAR) is measured. The X-ray pattern results reveal that the addition of Ag increases the crystallite size of Fe3O4/Ag composite nanoparticles to 25.4-32.6 nm. The Fourier transform infrared spectra results confirm the presence of Fe3O4/Ag composite nanoparticles. Magnetic measurements show that the samples have soft ferromagnetic properties at room temperature, with increased coercivity and reduced saturation magnetization after Ag addition. The bandgap energy of the Fe3O4/Ag nanoparticles is determined to be approximately 3.35 eV, which decreases to 2.99 eV after Ag addition. The SAR value of the nanoparticles is determined using a calorimetric method and varies from 0.81 Wg  1 to 2.12 Wg  1 under different alternating magnetic field (AMF) strengths. The saturation magnetization, frequency, and amplitude of AMF all influence the SAR value of the nanoparticles. Overall, the results indicate that the addition of Ag to Fe3O4 has a significant impact on the microstructural, optical, magnetic, and SAR properties of the nanoparticles, making them a promising candidate for use as a magnetic hyperthermia agent.