Room Temperature, Pbs, The Sb <sub> 2 </ Sub> S <sub> 3 </ Sub> Nanocrystalline Microstructure Controllable Synthesis And Characterization

The fabrication of semiconducting chalcogenides with well-defined size and morphology has attracted much attention in recent year because properties of materials are dependent on their morphologies and crystal structures. However, most of the preparation was completed via a hydrothermal process or at high temperature. In this dissertation, two typical semiconductors PbS and Sb2S3 with different morphologies were synthesized by low temperature simple route. The crystal phase and morphology of the products have been characterized by XRD, EDS, Raman, TEM, SEM and UV-vis spectra. The main contents and results are summaried as follows:(1) Lead sulfide nanocrystals:PbS cubes were easily produced from molecular precursors (xanthate) in ethylene diamine (en) solution at room temperature for aging 5 days, The TEM image shows that the morphology of the product is cubic. The average size of the cubes is 100 nm. The star-sharped PbS was synthesized at 80℃for 24h, under hydrothermal conditions, using xanthate and dimethyl sulphoxide(DMSO) as source materials. The products have a well-defined size and morphology. The result of XRD analysis shows that the structure of PbS nanocrystals is face-centered cubic.(2) Antimony sulfide (Sb2S3):By using single-source molecular precursors, ultralong Sb2S3 nanowires were easily synthesized at room temperature by employing ethylenediamine both as solvent. The diameter of nanowire is in the range of 5-10 nm. The photocatalytic experiment of the as-prepared Sb2S3 nanowires under visible light indicated that the photodegradation ratio of methyl orange and methylene blue in aqueous solution was up to 95%. Sb2S3 microspheres have been prepared 80℃by liquid-liquid interfacial route with the reaction of SbCl3 and CS2 using DMSO as solution.(3) A series of metal sulfides have been synthesized from molecular precursors (xanthate) in ethylene diamine solution:flower-like Bi2S3,CdS nanoplates and CoSxnanorods were obtained at room temperature, abelt-like ZnS and NiS hollow nanoprisms were producted at 60℃。The TEM images show that all of metal sulfides have well-defined nanostructures.