Fabrication and properties of poly(vinylidenefluoride)/PbS/Au heterogeneous nanostructures

We report on the fabrication of polyvinylidenefluoride (PVdF) PVdF/PbS and PVdF/PbS/Au heterogeneous nanostructures by the processes, electrospinning and chemical treatment. Initially electrospinning a solution consisting of PVdF and lead acetate was used to form PVdF nanofibers loaded with Pb ions. Exposure of Pb ions loaded PVdF fibers to H2S resulted in PVdF/PbS nanostructures. The deposition of gold nanoparticles onto PVdF/PbS nanostructures results in PVdF/PbS/Au heterogeneous structure. The existence of PbS particles with an average diameter of 11 nm is evident from field emission transmission electron microscopy (FETEM) image of PVdF/PbS. The results from X-ray diffraction of PVdF/PbS also predict the size of PbS particles as in accordance with FETEM. A blue shift in the optical transition of PbS is noticed in the UV-visible spectrum of PVdF/PbS as a result of quantum confinement effect. The band gap of PbS is influenced by the presence of Au nanoparticles over the PbS particles. An equal atomic weight % of Au and PbS is found in the PVdF/PbS/Au nanostructure as inferred from energy dispersive X-ray spectroscopy (EDX). Photoluminescence (PL) spectra of PVdF/PbS and PVdF/PbS/Au are compared. Emission peaks are noticed at 400 nm and 480 nm for PVdF/PbS and PVdF/PbS/Au nanostructures respectively for an excitation wavelength of 254 nm. The presence of Au nanoclusters in PVdF/PbS/Au diminishes the intensity of photo emission of PbS.