Optimization and spectroscopic studies of CdS/poly(vinyl alcohol) nanocomposites

Polyvinyl alcohol (PVA) capped CdS nanorods were prepared using solvothermal method which employed ethylenediamine as solvent. X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), transmission electron microscopy (TEM), Ultraviolet-visible (UV-vis) and fluorescence spectra were used to characterize the final nanorods product. X-ray results indicated the formation of CdS nanorods with hexagonal phase in PVA polymeric matrix. The prepared CdS nanorods were dispersed and nearly uniform in length and the diameter of the particles was confined within 222 +/- 5 and 33 +/- 2 nm, respectively. The optical properties have been studied by UV-vis and fluorescence. UV-vis absorption spectra were used to study the confined growth process of PVA-capped CdS nanorods. The absorption spectra showed a blue shift as compared to the bulk CdS band gap. Fluorescence measurement showed the emission band could be assigned to the optical transition of the first excitonic state of Cd nanoparticles. This band was shifted to higher energy with increasing of Cd2+. (C) 2008 Elsevier B.V. All rights reserved.