Preparation of Silver-Coated Silica Microspheres with High Electrical Conductivity Through Pyrogallol-Fe(Ш) Coordinated Surface Functionalization

Abstract

In this study, we report a facile method to fabricate silica-silver (SiO2/ PG-Fe3+/Ag) core–shell composite microspheres. The surface of SiO2 microspheres is functionalized with pyrogallol-ferric ions (PG-Fe3+) complexes, then Ag ions are reduced to Ag nanoparticles in situ onto the surface of SiO2 microspheres by electroless plating process. The Ag nanoparticles were uniformly coated on the surface of the SiO2 microspheres and formed a distinctive layer, which was confirmed by scanning electron microscopy characterization. The chemical compositions and microstructures of the microspheres were investigated by X-ray photoelectron spectroscopy and X-ray diffraction, respectively. The electrical conductivity of the prepared SiO2/ PG-Fe3+/Ag core–shell microspheres was about 1000 S/cm. When the microspheres were filled in methyl vinyl silicone rubber (MVQ), the obtained composites showed good mechanical and electrical properties, indicating their potential applications as conductive and electromagnetic shielding materials.