Study On The Controllable Synthesis Of Sulfide Semiconductor Nano-materials And Photocatalytic Properties

As a direct band gap semiconductor with Eg of 2.42eV at room temperature, CdS has beenpaid more attention for its excellent optical properties, offering commercial or potentialapplications in optics, electricity, magnetism, mechanics and catalysis. Therefore, the synthesisof nanometer CdS with the controllable size and appearance has become a research hot spotrecent yeas.In this thesis, CdS hollow microsphere (including ZnS) was successfully synthesized firstlyby the hydrothermal method with nature macromolecule chitosan as a "soft-template". Productswere characterized by Transmission Electron Microscope (TEM), Field Emission TransmissionElectron Microscope (FETEM), X-ray diffraction (XRD) and Ultraviolet-Visible diffusereflection spectrum (UV-Vis-DRS) technologies, respectively. The effects of temperature, themass fraction of chitosan, the source of S²⁺, molecular weight of chitosan on the formation ofCdS hollow microsphere were discussed. The mechanism of the formation of the hollowmicrosphere was analyzed and infered.Based on the above study, the synthesized CdS hollow microsphere was used in the processof chitosan degradation to provide a new effective approach for controllable synthesis of lowmolecular weight chitosan. The effect of the mass fraction of chitosan and the dosage of thecatalysis of CdS on chitosan degradation was discussed, and the mechanism of the degradationof chitosan was studied.In addition, Beause of extensive existence of surfactant in water, the visible-lightphotocatalytic activity of the catalysts was tested with Rhodamine B and methylorange as theobjective decomposition substance. The effects of the two kinds of representational anion-cationsurfactant sodium dodecyl sulfate and cetyl trimethyl ammonium bromide on photocatalyzingdegradation decolourization of Rhodamine B and methylorange were studied. The possiblemechanism of degradation was discussed in this paper. All of the activation studies attempted tobuild certain rationale for the photochemical catalysis efficiency enhancement and thephotochemical catalysis technology practical application.