Study On Degadation Of Gaseous Toluene By Photocatalytic Oxidation Of CH₃NH₃PbI₃ Supported On TiO₂

In recent years,the community is highly concerned about the environmental pollution problems caused by volatile organic compounds?VOCs?.With the advantages of low investment costs,low operating costs and simple operation and maintenance.TiO₂ photocatalytic oxidation method has a high application value in industry.However,the photo-generated electrons and holes,which produced by TiO₂ photocatalytic oxidation method,are easily to compound,affecting the degradation of VOCs.In this paper,CH₃NH₃PbI₃ was supported on TiO₂,which has supported on foam nickel mesh,and then formed CH₃NH₃PbI₃/TiO₂ films.The photocatalytic activity of CH₃NH₃PbI₃/TiO₂ films and the kinetics of degradation of toluene,which was taking as a representative compound of VOCs,and the degradation mechanism and inactivation effect experimentals were studied.The CH₃NH₃PbI₃/TiO₂ films supported on the foamed nickel mesh were prepared by solgel method and heat treatment method.The morphology,crystal structure,ingredient,surface structure and optical properties of CH₃NH₃PbI₃/TiO₂ films were characterized respectively by SEM,XRD,XPS,FTIR,UV-vis-DRS and PL.The results showed that the CH₃NH₃PbI₃/TiO₂ films were supported on the foam nickel network,and the TiO₂ in the CH₃NH₃PbI₃/TiO₂ films were anatase.Compared with TiO₂,CH₃NH₃PbI₃/TiO₂ films had not only higher UV absorption capacity,but also visible light absorption capacity.CH₃NH₃PbI₃ loaded on TiO₂ can improve the content of hydroxyl groups and surface adsorption water on the surface of the film,inhibited the recombination of photoelectrons and holes,and improved the photocatalytic activity.In the self-made photocatalytic reaction device,the kinetics of photocatalytic degradation of toluene was carried out.The results showed that the initial concentration of toluene,the catalyst load molar ratio,light source characteristics and light intensity have an impact on the photocatalytic degradation of toluene.Increasing the initial concentration of toluene,the photocatalytic degradation efficiency gradually decreased.When the initial concentration of250 mg/m3 of toluene,the degradation rate of toluene reached to 96%.When the load ratio were 0⁰.5%,the photocatalytic efficiency increased with the increasing of the load ratio,while the load ratio were 0.5%².0%,the photocatalytic efficiency decreased with the increasing of the load ratio,and the optimal load molar ratio was 0.5%.The degradation of toluene using UV185 nm + 254 nm lamp was better than UV254 nm.The higher the intensity of UVlight,the higher the degradation efficiency of toluene.The reaction paths of photocatalytic oxidation of toluene might be as follows: toluene was degraded to a small amount of intermediates,such as benzaldehyde,etc.,and then continued to mineralization into CO2 and H2 O by photocatalytic reaction.