Electrospinning Synthesis And Characterization Of Metallic Chalcogenides

Nanoscale-sized metallic chalcogenides have wide applications in the fields of photocatalysis, sensors, solar cells, light-emitting diode (LED), biological detection, fluorescence probe and semiconductor devices owing to their unique chemical and physical properties. Nowadays, research on nanoscale-sized metallic chalcogenides are focused on quantum dots and nanocrystals. However, one-dimensinal or quasi one-dimensinal nanomaterials have many attractive properties. In order to study the properties of these nanomaterials, a preparation technique of nanoscale-sized metallic chalcogenides nanofibers and nanobelts is imperatively needed. Electrospinning is the best choice to prepare one-dimensional nanomaterials due to its simplicity and reproducibility.ZnO, NiO. CdO nanofibers and nanobelts were fabricated by electrospinning in this dissertation. ZnS, NiS. CdS nanofibers and nanobelts were prepared by electrospinning combined with sulfurization method. ZnSe monodispersed particles, nanofibers and nanobelts were obtained by double crucible selenidation on the basis of ZnO nanofibers and nanobelts. Photocatalytic activity and the electric properties of these materials were studied.As-prepared samples were charactered by XRD, SEM. UV-Vis. Broadband dielectric spectrometer. The results showed that hexagonal ZnO. cubic NiO and cubic CdO nanofibers and nanobelts were obtained by calcination of the relevant PVP/Zn(NO3)2, PVP/Ni(NO3)2and PVP/Cd(NO3)2composite nanofibers and nanobelts, respectively. ZnS. NiS and CdS nanofibers and nanobelts were synthesized by sulfurization at700℃for lh using CS2as the sulfurization agent. All of them were hexagonal in structure. The mean diameters of sulfides nanofibers were ca.60-230nm, The mean width and thickness of sulfide nanobelts is ca.1.5-4.5μm and80-390nm, respectively. ZnSe monodispersed particles were obtained by double crucible selenidation at700℃for4h on the basis of ZnO nanofibers, these monodispersed particles of2.3±0.15μm in average diameter were cubic in structure. ZnSe nanofibers were synthesized by selenidation at700℃for3h on the basis of ZnO nanofibers, and the mean diameter of cubic ZnSe nanofibers is ca.103.6±13.1nm. ZnSe nanobelts were acquired by selenidation at700℃for4h on the basis of ZnO nanobelts, ZnSe nanobelts of1.34±0.3μm in average width and63.3nm in mean thickness were cubic in structure. These nanomaterials have excellent photocatalytic activity, and their electric properties were also studied.