Study On Preparation,Characterization And Visible Light Photocatalytic Activity Of CPVC-TiO₂

PVC-TiO2 film were prepared by ultrasonic method using PVC tetrahydrofuran solution and TiO2 particles.A new visible light photocatalyst has been prepared by conjugated polymer derived from polyvinyl chloride(PVC)via thermal-treatment at 125℃ for 3h and characterized by X-ray diffraction(XRD),Scanning Electron Microscope(SEM),UV-visible diffuse reflectance spectroscopy(UV-Vis DRS),Photoluminescence(PL)and High Performance Liquid Chromatography(HPLC).XRD results show that the crystallization performance of TiO2 particles modified by CPVC didn’t change.DRS results reveal that CPVC can increase the visible light absorption ability.Fluorescence emission spectrum shows that CPVC attached to the surface of TiO2 reduces composite possibility of the light electrons and holes composite risk.IR shows that PVC does not completely remove HCl when it forms conjugated polymer,and conjugated polymer derived from polyvinyl chloride is partly on the surface of TiO2.The photocatalytic activities of CPVC-TiO2 composites were studied by degradation of rhodamine B.the rate constant(k)for the degradation of rhodamine B photocatalyzed by CPVC-TiO2 composites is about 6 times of that by CPVC,which indicates that the CPVC-TiO2 composites has outstanding visible light photocatalytic activities.The recycling runs experiment shows that the photocatalytic stability of CPVC-TiO2 composites is excellent.The paper discusses some conditions affected by the photocatalytic activities of CPVC-TiO2 composites,such as heat treatment temperature,heat treatment time and so on.The results showed that CPVC-TiO2 composite film have perfect photocatalytic activity when the thermal treatment is 125 ℃ and the thermal time is 3h,the pH is alkaline 9.0 and light intensity range is 360-500 nm.The carriers scavenger experiment indicated that the photogenerated holes might be the main active species in RhB photodegradation.Plans to adopt the method of simple preparation for CPVC body by surface covering different amount of TiO2 formed CPVC-TiO2 thin film.The composite film structure and properties were characterized by Scanning Electron Microscope(SEM),High Performance Liquid Chromatography(HPLC).The photocatalytic activities of CPVC-TiO2 composites were studied by degradation of Rhodamine B.The results showed that TiO2 modified by polyvinyl chloride can increase visible light absorption,improve the utilization ratio of visible light,possesse higher photocatalytic activity and stability.The degradation rate of Rhodamine B solution photocatalyzed in visible light by CPVC-TiO2 composites is about 2 times of that by CPVC when the surface coverage of CPVC and TiO2 is 100%.