Study Of Preparetion And Activity Of Nano Sulfide-Potassium Titanate

K₂Ti₄O₉, a two-dimensional layered compound photo-catalyst, cannot absorb visiblelight due to its relatively large band gap. Introducing a narrow band-gap semiconductorinto the layered space is a common method of increasing the visible light response forK₂Ti₄O₉. The narrow band-gap semiconductor not only acts as the sensitizer, but alsoreduces the recombination rate of the photo-generated electron-hole pair and gives rise toan enhancement of the photo-catalytic activity. However, one of the main drawbacks is acomplicated synthesis procedure, and the structure of the layered compound may bechanged dramatically after intercalation. Consequently, it is of great importance to adopta simple and fast synthesis procedure on the basis of not changing the crystal form oflayered compound to enhance the photo-catalytic activity in the visible region.CdS/K₂Ti₄O₉were prepared by the deposition-precipitation method. The photo-catalytic activities for hydrogen evolution were investigated under visible light. Theabsorption edge of K₂Ti₄O₉shifted to the visible light region after the deposition of CdS.The composite photo-catalyst loaded with25wt.%CdS showed the highest activity. Theamount of hydrogen evolution is1.56mmol/g illuminating3h of0.5g catalyst.PbS/K₂Ti₄O₉were prepared by dipping-precipitation method. Their photo-catalyticactivities were investigated under visible light. The results indicate that the size of PbS,which uniformly scattered on the surface of K₂Ti₄O₉, distribute in the range of50-100nm.PbS/K₂Ti₄O₉shows lower PL peak intensity than K₂Ti₄O₉. The composite photo-catalystloading25wt.%PbS shows the highest photo-catalytic activity. The amount of hydrogenevolution is1.85mmol/g illuminating3h of0.5g catalyst.Cd_1-xZn_xS/K₂Ti₄O₉were prepared by dipping-precipitation method. Thephotocatalytic activities for degradation of Rhodamine B （RhB） were investigated undervisible light irradiation. Cd0.8Zn0.2S, in the series of Cd_1-xZn_xS solid solution, shows thehighest activity. The composite photocatalyst loaded with30wt.%Cd0.8Zn0.2S exhibitedthe highest photo-catalytic activity, and was able to degrade95%of RhB in180min. Themechanism of Cd0.8Zn0.2S/K₂Ti₄O₉composite was discussed.