Enhancement of electric conductivity by incorporation of Ag into core/shell structure of Fe3O4/Ag/PPy NPs

Core–shell structure of Fe3O4/Ag/polypyrrole (PPy) nano-particles (NPs) was prepared by a facile method through the redox reaction of silver nitrate and pyrrole in the presence of polyvinyl pyrrolidone (PVP) as protection agent. The presence of PVP has an effect on the morphology and structure of the Fe3O4/Ag/PPy NPs. Rod-shaped Fe3O4/Ag/PPy NPs were obtained with the increase of the concentration of PVP to 0.125 mM, in which the wire-like core was formed by the aggregation of Fe3O4 and Ag nanoparticles. At the same time, the PPy shell of the NPs became more uniform and thicker with the increase of the concentrations of PVP and AgNO3 in the solution. The electric conductivity of the NPs can be enhanced to 335 ± 8 S/cm by incorporation of the Ag into the NPs. At the same time, the thickness of the PPy shell affects the electric conductivity of the samples. All the NPs in the present work exhibit superparamagnetic behavior.