pH-Mediated Synthesis and Mechanistic Study of Homogeneous Magnetic Ag@Fe₃O₄ Nanoparticles.

In this paper, we report a novel kind of pH-mediated homogeneous magnetic Ag@Fe₃O₄ nanoparticles prepared by facile one-pot synthesis. The nanostructure and surface element composition along with magnetism of the as-synthesized hybrid nanoparticles can be easily adjusted by pH value in synthetic process. Furthermore, XRD and XPS detections indicated that the two components in the nanoparticles are both independent and certain synergistic. Compared with magnetic silver nanoparticles prepared by traditional multi-step methods, the homogeneous Ag@Fe₃O₄ nanoparticles showed excellent monodispersity and stability. Moreover, corresponding formation mechanism of the homogeneous hybrid magnetic nanoparticles was demonstrated in detail. Catalytic application of the homogeneous hybrid nanoparticles prepared under different pH values also verified rationality of the formation mechanism from side. This research provides a general strategy for constructing and large-scale preparing homogeneous magnetic hybrid metal nanoparticles.