Study On Preparation,Characterization And Visible Light Photocatalytic Activity Of AgBr/CPVC And AgBr/PANI

AgBr particles were prepared by double jet method using NaBr aqueous solution and silver ammonia solution.A new visible light photocatalyst has been prepared by conjugated polymer derived from polyvinyl chloride(PVC)via thermal-treatment at 1500C for 2h and characterized by X-ray diffraction(XRD),X-ray photoelectronm spectroscopy(XPS),UV-visible diffuse reflectance spectroscopy(UV-Vis DRS).XRD results show that the crystallization performance of AgBr 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 AgBr reduces composite possibility of the light electrons and holes composite risk.XPS 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 AgBr.XRD,DRS and XPS show that CPVC attached to the surface of AgBr can slow AgBr decomposition in the process of photocatalytic reaction.The photocatalytic activities of AgBr/CPVC composites were studied by degradation of methyl orange.the rate constant(k)for the degradation of methyl orange photocatalyzed by AgBr/CPVC composites is about 2 times of that by AgBr,which indicates that the AgBr/CPVC composites has outstanding visible light photocatalytic activities.The recycling runs experiment shows that the photocatalytic stability of AgBr/CPVC composites is excellent.The paper discusses some conditions affected by the photocatalytic activities of AgBr/CPVC composites,such as mass ratio of AgBr/CPVC,heat treatment temperature,heat treatment time,initial concentration of methyl orange solution and the addition amount of catalyst and so on.The results showed that AgBr/CPVC composite particles have perfect photocatalytic activity when quality ratio of AgBr and PVC is 800 to 1,the thermal treatment is 150? and the thermal time is 2h.The degradation rate is found to increases at first and then decreases in initial concentration of the MO from 5 to 25 mg·L-1.The effect of catalyst dosage on the photocatalytic degradation of MO was studied by varying the amount of Ag/AgBr from 1 to 5 g·L-1 and the results indicated that the degradation rate increases with increasing the catalyst dosage.The carriers scavenger experiment indicated that the photogenerated holes might be the main active species in MO photodegradation.AgBr/PANI visible catalyst were prepared by chemical oxidation in situ polymerization.The composite particles structure and properties were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopic analysis(XPS)and UV-visible diffuse reflectance spectroscopy(UV-Vis DRS).The photocatalytic activities of AgBr/PANI composites were studied by degradation of methyl orange.The results showed that AgBr modified by polyaniline can increase visible light absorption,improve the utilization ratio of visible light,slow down the decomposition of AgBr and possesse higher photocatalytic activity and stability.the degradation rate of methyl orange solution photocatalyzed in visible light by AgBr/PANI composites is about 2 times of that by AgBr when the mass ratio of AgBr and aniline is 100:1.