Preparation Of Modified BiOBr And Its Photocatalytic Degradation Of Benzene Series

With the rapid development of China’s social economy and industrial enterprises,the two major problems of environmental pollution and energy crisis have become increasingly prominent.In recent years,photocatalytic oxidation technology has become more and more widely used in the treatment of environmental pollution,and there has been further development in the degradation of volatile organic compounds(VOCs).Among semiconductor photocatalytic materials,BiOBr,a new material,has attracted extensive attention due to its excellent electronic structure,light absorption properties and good catalytic performance.However,BiOBr has a wide bandgap(-2.90 eV)and has limited absorption range for visible light,which limits its practical application under visible light conditions.In order to improve the photocatalytic activity of BiOBr in visible light,the development of high-performance modified BiOBr photocatalytic materials has become the key to solve the problem.At present,the semiconductor photocatalyst modification methods mainly include semiconductor compounding,photosensitizing,precious metal deposition and metal ion doping.The modified catalyst has a wider range of response to visible light and can perform photocatalytic degradation of organic pollutants in the visible light range,and thus has attracted the attention of many researchers.With the declining air quality year by year,the problem of air pollution has received increasing attention.Among them,volatile organic pollutants(VOCs),which are the main components of indoor air pollution and smog,are highly concentrated in the air and are difficult to degrade.It will be a major hazard to the environment and the human body,and has become a key research subject in the field of environmental purification.In recent years,it has been found that semiconductor photocatalysis can use light energy to degrade organic pollutants,which is of great significance to air remediation.In this experiment,pure BiOBr was prepared by the direct hydrolysis method,AgBr/BiOBr with different metal loadings was prepared by ion exchange method,and the Ag/AgBr/BiOBr composite photocatalyst was irradiated by AgBr/BiOBr with different loadings.,and the use of XRD,SEM,TEM,BET and other characterization methods for the preparation of the sample system to study the load of different photocatalyst structure,morphology,specific surface area and light absorption properties.The results show that the BiOBr semiconductor material prepared by the hydrolysis method belongs to the tetragonal crystal system,the morphology is irregular nanosheet,the crystallinity is good,and the lattice fringes are clear.With different loadings,the morphology of the photocatalyst varies to varying degrees.The AgBr/BiOBr with a loading of 1/16 is the most uniform and well dispersed,with the largest specific surface area.The results of photocatalytic degradation of benzene series at different catalyst dosages and initial concentrations of different benzene series showed that under the irradiation of UV lamp,the amount of catalyst was increased within a certain range,and the photocatalytic degradation efficiency of benzene series was obvious.Increase,but when the amount of catalyst is too large,the photocatalytic degradation efficiency is not very obvious.Changing the initial concentration of benzene series increased the photocatalytic degradation efficiency,but with the increase of the initial concentration of benzene series,the photocatalytic degradation efficiency of BiOBr decreased.In this experiment,the kinetics of the photocatalytic degradation of the benzene series of the BiOBr team was studied.The results show that the process of photocatalytic degradation of the benzene series by BiOBr conforms to the first-order reaction kinetics equation.This experiment explored the effect of composite catalysts with different loadings on the photocatalytic efficiency.The experimental results of photocatalytic degradation of benzene series showed that when the loading of AgBr is 1/16,AgBr/BiOBr and Ag/AgBr/The photocatalytic degradation efficiency of benzene series was highest with the BiOBr composite catalyst.The photocatalytic degradation efficiency of benzene was 95.51%for AgBr/BiOBr with 1/16 loading,and the AgBr loading was 1/16.The photocatalytic performance of Ag/AgBr/BiOBr is best,and the photocatalytic efficiency of benzene can reach 97.91%.