Construction And Performance Of Metal Chalcogenides Low-dimensional Nanostructures

Metal chalcogenides have wide applications in the fields of photocatalysis, solar cells, infrared detectors and electrode materials owing to their unique properties. Nowadays, many methods have been successfully employed for fabrication of metal chalcogenides with different morphologies, and the construction of low-dimensional materials has become one of the hot topics in the field of materials science. Electrospinning has been proved to be an important method to fabricate low-dimensional nanomaterials due to its convenient operation and high reproducibility. Hence, fabrication of metal chalcogenides low-dimensional nanomaterials via electrospinning remains an important and creative subject of study.In this thesis, PVP/inorganic salts composite nanofibers were fabricated by electrospinning, and SnO2, Sb2O4, PbO and CuO naonfibers were acquired by calcination of relevant PVP/inorganic salts composite nanofibers. SnS, Sb₂S₃, PbS, CuS and Cu7.2S4 nanofibers were obtained by double-crucible sulfurization method on the basis of oxide nanofibers. SnSe, SnO2/SnSe₂, Sb2Se₃, PbSe and Cu₂-xSe nanofibers were fabricated by double-crucible selenidation technique using the oxide nanofibers as precursors. Bi₂Se₃/PANI/PVP composite nanofibers were prepared by the solvothermal method combined with electrospinning. The as-prepared samples were characterized by XRD, SEM, EDS and HMS, etc. The results show that metal oxide nanofibers, metal sulfides nanofibers and metal selenides nanofibers were of pure phases, and their diameters were respectively in the ranges of 60-230 nm, 120 nm-300 nm and 90 nm-270 nm.The photocatalytic activities of samples were studied by using rhodamine B?Rh B? as degradation agent. When SnS, SnSe or SnO2/SnSe₂ nanofibers are used as the photocatalysts, the degradation rate of Rh B solution under the UV light irradiation for 200 min are respectively 92.55 %, 92.86 % and 68.38 %. While the degradation rates of Rh B solution using Sb₂S₃ or Sb2Se₃ nanofibers after 220 min irradiation reach 91.21 % and 75.20 %, respectively. When PbS or PbSe nanofibers are employed as the photocatalysts, the respective degradation rates of Rh B solution after 220 min irradiation are 70.79 % and 73.17 %. When CuS, Cu7.2S4 or Cu₂-xSe nanofibers are used as the photocatalysts, the degradation rates of Rh B solution after 240 min lighting are 64.77 %, 78.13 % or 63.83 %, respectively. HMS test shows that Bi₂Se₃/PANI/PVP nanofibers have high conductivity. These meaningful results lay a solid foundation for the further research of metallic chalcogenides low-dimensional nanomaterials.