| In this article, hollow photocatalyst is intrducedd, Based on this structure of hydrophobic, make catalyst float easily in wastewater,thus having the ability of the absorption of light radiation and contacting well with the ability of the absorption of light radiation and contacting well with the gas phase and liquid phase with the modification of the structure of hydrophobic. Solve the problem of poor light penetration.Based polystyrene as the stencil plate, the suface of hollow TiO2 have a layer of SiO2 andmake hydrophobic.We determined the best conditions of the preparation by decolorizing effect of simulated the best condition of the preparation by decolorizing effect of simulated wastewater with a single catalytic the optimal conditions were as follows: SiO2 core-shell TiO2 radio of 2:5,the silane coupling agent KH570 SiO2/TiO2 ratio of 1:4 which had a better photocatalytic performance. Through TEM the internal TiO2 hollow structure on the surface evenly coated a layer of material is detected..FT-IR showed that absorption peak of Si-O vibration appeared at 811cm-1 and 1112 cm-1, prove the material coated on the surface of the hollow TiO2 material is SiO2, then absorption peak of C=O and Si-O stretching vibration silane belongs to coupling agent KH570 appeared at 1123 cm-1 and 1727 cm-1 which showed that there was a chemical bond between KH570 and SiO2/TiO2, grafting success.XRD showed that crystal type of catalyst were mainly anatase type,this structure is unaffected in this process of modification.We measured the contact angle of different silane coupling agent and hydrophobic hollow SiO2/TiO2 photocatalyst with contact angle tester tests,it is concluded that contact angle of m(KH570):m(hollow SiO2/TiO2) for 1:4 was 88±2°, the contact Angle can make the stability of the modified catalyst float on water surface and contact with the gas phase and liquid phase at the same time.We compared the decolorization effect of SiO2/TiO2 and TiO2 which made at different time dosage of catalyst pH,the initial concentration of liquor and the reaction speed of light intensity with the theory of kinetic parameter the conclusion can be drawn as followed.The catalyst in various condition above conformed to the first order kinetics equation,when the concentration of simulated wastewater was 10mg/L,the equation,the Ln(At/Ao)=-0.1883x+0.0682, R2=0.9967,the decolorization rate of the hydrophobic hollow SiO2/TiO2 photocatalysis reached 2.7 times of TiO2 hollow; when the density of hydrophobic hollow SiO2/TiO2 is 2.5%, the equation Ln(At/Ao)-0.4833x+0.5354, R2=0.993,the decolorization rate of the hydrophobic hollow SiO2/TiO2 photocatalysis reached 1.9 times of TiO2 hollow; when the pH was 2, the equation Ln(At/A0)=-0.6099x +0.8957, R2=0.9725, the decolorization rate of the hydrophobic hollow SiO2/TiO2 photocatalysis reached 3.59 times of TiO2 hollow; when 10cm, the equation Ln (At/Ao) =-0.4207x+0.629, R2=0.9793, the decolorization rate of the hydrophobic hollow SiO2/TiO2 photocatalysis reached 2.14 times of TiO2 hollow.The coloured paper wastewater was dealt at different time the dosage of catalyst,the pH,the light intensity and the amount of waste water to research the impact of the conditions on the decolorization rate of hydrophobic hollow SiO2/TiO2 photocatalysis and the removal rate of COD with the waster, he result is as follows:The light-catalyzed reaction lasts for 4 hours was best. With the amount of the hydrophobic hollow SiO2/TiO2 used as photocatalyst can properly be reduced and don’t effect the final decolorization rate.Therefore, resource is conserved and cost is reduced. |
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