Large-scale fabrication of Ag nanoparticles in PVP nanofibres and net-like silver nanofibre films by electrospinning

Heat treatment of various compositions of AgNO3-doped polyvinylpyrrolidone (PVP) composite nanofibres fabricated by electrospinning produced two kinds of silver species: (i) Ag nanoparticles dispersed in PVP nanofibres, when the loading of AgNO3 was 5 wt%, and (ii) a net-like silver nanofibre film when the loading of AgNO3 was five times greater than that of PVP in the composite nanofibres. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible absorption spectroscopy, FT-IR spectra, powder x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS) were used to characterize the silver nanoparticles and nanofibres. The formation mechanisms are discussed based on the redox reaction between AgNO3 and PVP during heat treatment; essentially, the weight ratios of AgNO3 to PVP determined the types of morphologies, from Ag nanoparticles to silver nanofibre film. The present results may find some potential application in the design of new composite materials in the dielectric and electronics areas.