Synthesis, Characterization And Photocatalytic Properties Analysis Of ZnS Nanomaterials

ZnS is an important direct wide-band gap II-VI semiconductor material, which is mainly exists in the form of Zinc blende structure or Wurtzite structure in nature. The exciton binding energy of Zinc blende structure ZnS is3.54eV at room temperature(300K), and the Wurtzite structure ZnS is3.71eV at room temperature. With the development of science and technology, the nanoscale semiconductor material ZnS is becoming a hot spot in research fields, which is widely used in photoluminescence, electroluminescence, sensor and photocatalysis fields. Photocatalysis is a new way in the treatment of environmental pollution over the last several years, which is at the forefront field of nanoscale semiconductor material.There are many literature reports about the synthesis methods of ZnS, such as chemical vapor deposition method, magnetron sputtering, microemulsion mediated solvothermal, but those above methods are complicated, the production cycle is long, the production costs is high and the repeatability is low. In this paper, I synthesized ZnS nanospheres with simple hydrothermal method, synthesized ZnS nanorods with solvothermal method and synthesized Ag/ZnS core-shell nanorods creatively. Further more, the element, morphology, possible formation mechanism, photocatalytic properties of the synthesized products are analyzed. The main results are as follows:1. The zinc-blende ZnS nanospheres were synthesized by bydrothermal method with CTAB as surfactant, the effect of reaction time on the size of ZnS nanospheres are discussed. The ZnS nanospheres formed by self-assemble with the action of PVP. The intensity of the UV absorbtion peak rose up with the growth of the size of ZnS nanospheres, and the peaks show blue shift. The photoluminescence peaks are at about480nm. The photocatalytic testing shows that the ZnS nanospheres synthesized by12hours has the best photocatalytic properties, meanwhile, the photocatalytic properties of synthesized nanoscale ZnS material is much better than normal ZnS powder.2. Synthesized ZnS nanorods by solvothermal method with PVP as surfactant. The ZnS nanoparticles grow along the direction perpendicular to (100) crystal face under the effect of PVP, and then the nanorods structure formed. The UV absorbtion peak of the ZnS nanorods is at about340nm, and the photoluminescence wavelength is about470nm. The photocatalytic properties of the ZnS nanorods are weaker than ZnS nanospheres, but still better than ordinary ZnS powder.3. Synthesized Ag/ZnS core-shell nanorods to improve the the photocatalytic properties of ZnS nanoscale materials. The formation mechanism of Ag/ZnS core-shell nanorods is that:the synthesized Ag nanowires were covered by ZnS nanoparticles owing to the effect of CTAB, then the ZnS nanoparticles grow up, the core-shell nanorods are formed. The UV-vis test results show that the absorbtion ability of synthesized Ag/ZnS nanorods is much better than that of ZnS nanospheres. The results of photocatalytic degradation experiments confirm that the degradation ability of Ag/ZnS nanorods is much better than ZnS nanospheres.