The Influence of Experimental Conditions on the Formation of ZnO Fibers by Electrospinning†

The influence of experimental conditions on the formation of ZnO fibers by electrospinning has been investigated. The electrospinning of a viscous suspension containing polyvinylpyrrolidone and zinc acetate in C2H5OH/H2O produced very long fibers (several hundred μm). Upon calcination a thin deposit of precursor fibers at 400 or 500 °C for 1 h the fibers consisting of ZnO nanoparticles were obtained. On the other hand, ZnO fibers were not obtained upon heating a thick deposit of precursor fibers at 600 °C for 6 h. At all three heating temperatures (400, 500 or 600 °C) ZnO nanoparticles with a gradual increase in size were produced. The Raman spectrum of ZnO nanoparticles formed at 600 °C showed additional bands which were assigned to graphene oxide. It was suggested that in the thick deposit the organic component did not burn out completely, i.e., the residual carbon (graphite) transformed into graphene oxide for the experimental conditions applied.