Of Sb <sub> 2 </ Sub> S <sub> 3 </ Sub>, Of Ceo <sub> 2 </ Sub> Nanocrystals And Performance Research

In this dissertation, the microstructure control of Sb₂S₃ and CeO₂ semiconductors, and the photocatalysis properties of CeO₂ /TiO₂ under UV irradiation and Sb₂S₃ under visible light with methyl orange as polluted water were studied, and the main contents and results are discussed as follows:Large-scale rod-like antimony sulfide (Sb₂S₃) dendrites have been prepared by hydrothermal method using antimony chloride (SbCl₃), citric acid and thioacetamide as raw materials at 160℃for 12 h. The powder X-ray diffraction pattern shows the Sb₂S₃ crystals belong to the orthorhombic phase with calculated lattice parameters a=1.120 nm, b=1.128 nm and c=0.3830 nm. The quantification of energy dispersive X-ray spectrometry analysis peaks gives an atomic ratio of 2:3 for Sb:S. Transmission electron microscopy micrographs studies reveal the appearance of the as-prepared Sb₂S₃ is dendrites-like which is composed of nanorods with the typical width of 300-500 nm and length of 5-20μm. Finally the influences of the reaction conditions are discussed and a possible mechanism for the formation of rod-like Sb₂S₃ dendrites is proposed.Antimony sulfide (Sb₂S₃) nanorods with diameter 30 nm have been prepared by the reaction of antimony chloride (SbCl₃) and potassium O-benzyl dithiocarbonate (benzylxanthate, KS₂COC₇H₇). Peanut-shaped Sb₂S₃ superstructures have been synthesized via a hydrothermal process at 120℃for 8 h under acidic conditions using KS₂COC₇H₇ as raw materials. Finally the influences of the reaction time and temperature on the formation of peanut-like Sb₂S₃ are discussed. The photocatalytic activity of Sb₂S₃ with different morphologies under visible light with methyl orange had been studied. The degradation of rod-like Sb₂S₃ is 71.17% in 1 h, while the peanut-like Sb₂S₃ is only 10.8%.Polyhedral ceria have been prepared by precipitation using cerium nitrate and ammonia as raw materials at 80℃for 3 h. The influences of the reaction time and temperature on the formation of polyhedral ceria are discussed. CeO₂/TiO₂ heterojunctions with different mass ratios were prepared by the coprecipitation process. The photocatalytic activity of CeO₂/TiO₂ under UV irradiation with methyl orange as pollutant water was studied. It was found that photocatalytic activity of CeO₂(3% wt)/TiO₂ was the best, and the degradation time was 10 min shorter than using pure TiO₂.