Large-scale fabrication and application of magnetite coated Ag NW-core water-dispersible hybrid nanomaterials

Abstract

In this work, we report a large scale synthetic procedure that allows attachment of magnetite nanoparticles onto Ag NWs in situ, which was conducted in a triethylene glycol (TREG) solution with iron acetylacetonate and Ag NWs as starting materials. The as-prepared Ag NW/Fe₃O₄ NP composites are well characterized by SEM, TEM, XRD, XPS, FT-IR, and VSM techniques. It was found that the mass ratio of iron acetylacetonate to Ag NWs plays a crucial role in controlling the amount of magnetite nanoparticles decorated on the Ag NWs. The resulting Ag NW/Fe₃O₄ NP composites exhibit superparamagnetic properties at room temperature, and can be well dispersed in aqueous and organic solutions, which is greatly beneficial for their application and functionality. Thus, the as-prepared magnetic silver nanowires show good catalytic activity, using the catalytic reduction of methylene blue (MB) as a model reaction. Furthermore, the Ag NW/Fe₃O₄ NP composites can be functionalized with polydopamine (Pdop), resorcinol–formaldehyde resin (PFR), and SiO₂, respectively, in aqueous/ethanol solution. Meanwhile they can also be coated with polyphosphazene (PZS) in organic solution, resulting in a unique nanocable with well-defined core shell structures. Besides, taking Ag NW/Fe₃O₄@SiO₂ as an example, a hollow magnetic silica nanotube can be obtained with the use of Ag NWs as physical templates and a solution of ammonium and H₂O₂. These can greatly improve the application of the Ag NW/Fe₃O₄ NP composites. The as-synthesized above nanocomposites have high potential for applications in the fields of polymers, wastewater treatment, sensors, and biomaterials.