Synthesis, surface modification, and characterization of Fe ₃ O ₄ @SiO ₂ core@shell nanostructure

Abstract

Abstract In recent times, nanoparticles have been the focal point of research in nanoscience due to their wide scope of potential applications in all fields of science. Iron oxide (Fe 3 O 4 ) nanoparticles (NPs) show incredible magnetic saturation, stability, biocompatibility, and intuitive properties on the surface, which makes them ideal for being utilized in several ways. In the present study, Fe 3 O 4 NPs were synthesized by co-precipitation and further coated with silica (SiO 2 ) to avoid aggregation. Synthesized nanoparticles (Fe 3 O 4 @SiO 2 ) were individually functionalized using glycine and malonic acid and characterized by various spectroscopies and microscopies techniques. XRD diffraction analysis showed that the presence of SiO 2 did not alter the diffraction pattern peaks, which represented the existence of Fe 3 O 4 . The presence of Fe 3 O 4 and SiO 2 nanoparticles were further confirmed using EDS. Transmission electron microscope micrographs of the synthesized nanoparticles exhibited spherical shape and confirmed the increase in particle size after coating with SiO 2. Also, the analysis of dynamic light scattering showed that the particle size of Fe 3 O 4 @SiO 2 functionalized with malonic acid (229.433 nm) was greater than those functionalized with glycine (57.2496 nm). However, the surface area was greater in Fe 3 O 4 @SiO 2 -glycine (104.8 m 2 /g) than Fe 3 O 4 @SiO 2 -malonic acid (26.15 m 2 /g). The key findings suggest that the synthesized core-shell Fe 3 O 4 @SiO 2 nanoparticles are a promising candidate for a wide array of applications in the field of medicine and environmental science.