【摘要】 研究了CdS/TiO2光催化的耦合效应.以TiO2、CdCl2和Na2S为原料在200℃、6h水热反应条件下一次合成CdS含量不同的CdS/TiO2,通过XRD、SEM、EDS和IR对样品进行表征,并通过谢乐公式(Scherrerequation)估算出样品晶粒的粒径.XRD图表明CdS/TiO2为锐钛矿型TiO2、立方相和六方相CdS的混合相.SEM表明CdS粒径为20～50nm,TiO2粒径为50～100nm.通过罗丹明B(rhodamineB)光降解脱色,表征了样品的光活性,结果表明当CdS∶TiO2为1.0时,CdS/TiO2开始出现耦合效应,当CdS∶TiO2为1.5时,CdS/TiO2的光活性最强,在30min内紫外光降解4mg·L-1罗丹明B溶液的降解率达74.3%.更多还原

【Abstract】 The coupled effect of photocatalytic activity of CdS/TiO₂ composite semiconductor was studied.CdS/TiO₂ nano-powders with different ratios of CdS∶TiO₂ from 0.005 to 2.0 were synthesized by the hydrothermal method at 200 ℃ for 6 h using titania, cadmium chloride and sodium sulfide as reactants. The CdS/TiO₂ powders were characterized by XRD, SEM, EDS, IR and the diameter of the particles was evaluated by Scherrer equation. XRD patterns showed that the crystallinestate of CdS/TiO₂ samples was a mixture of anatase, zinc-blend and wurtzite. SEM micrographs showed that the diameter of CdS particles was 20—50 nm and the diameter of TiO₂ particles was 50—100 nm. The photocatalytic activities of CdS/TiO₂ nanopowders were measured by photo-degradation of rhodamine B. When the mole ratio of CdS∶TiO₂ was 1.0, the coupled effect of photocatalytic activities appeared.When the mole ratio of CdS∶TiO₂ was 1.5, the coupled effect became the strongest, and the degradation rate of rhodamine B(4 mg·L^-1) irradiated by ultraviolet ray for 30 minutes was 74.3%.更多还原