Preparation Of Bismuth Oxychloride Oxidized Material And Its Photocatalytic Properties

BiOX,a new photocatalyst,has been extensively studied because of its stable structure and excellent optical properties.The traditional treatment methods of benzidine include physical adsorption,chemical oxidation and biological methods.However,these methods are not thorough for the degradation of organic matter,and the residual pollutants will continue to exist,thus causing secondary pollution to the environment..Photocatalytic technology has many advantages,including simple and clear process flow,less energy consumption,convenient and fast operation,complete degradation and so on,which can eliminate the possibility of secondary pollution.However,bismuth halide-based photocatalysts are difficult to be stimulated by sunlight because of their wide band gap.In this paper,BiOX was modified by structure modification,composite modification and loading on fly ash beads to enhance the visible light photocatalytic performance of the catalyst and solve the recycling problem.The research contents of this paper are as follows:1.Flower-like BiOCl with oxygen vacancies was synthesized by solvothermal method using glycerol as reaction solvent and Bi?NO₃?₃·5H₂O as bismuth source.Glycerol,as a template and reaction solvent in the preparation process,has higher photocatalytic activity than BiOCl synthesized by traditional hydrothermal method.The results are as follows:Firstly,the degradation of benzidine by flower-like oxygen vacancy BiOCl is first-order kinetics,and its photocatalytic activity is better than that of white BiOCl prepared by hydrothermal method,and it still maintains a stable degradation rate after four cycles of degradation,and its recycling performance is excellent.In addition,the main active species for photocatalytic degradation of benzidine are·OH and·O₂^-.2.BiOCl,BiOBr and PVP/BiOCl/BiOBr photocatalysts were synthesized by ethylene glycol solvothermal method.Electron microscopy showed that the morphology of the prepared catalyst was stacked layer by layer,and the size of the catalyst was 2 microns.The degradation of benzidine by PVP/BiOCl/BiOBr conforms to the first-order kinetics,exhibits good degradation performance under visible light,and maintains stable photocatalytic activity during four cycles of degradation.At last,the photocatalytic mechanism was studied and discussed in detail.3.PVP/BiOCl-FACs,PVP/BiOBr-FACs and PVP/BiOCl/BiOBr-FACs were synthesized by using ethylene glycol and fly ash cenospheres as matrix.The results of electron microscopy showed that the supported catalyst PVP/BiOCl/BiOBr-FACs was a flower-like PVP/BiOCl/BiOBr catalyst with a particle size of 2 micron covering a 100-micron sphere.The photocatalytic degradation of benzidine by PVP/BiOCl/BiOBr-FACs accords with the first-order kinetics reaction,and its reusability performance is high.The photocatalytic performance is stable in four photolysis experiments.Compared with the unimmobilized PVP/BiOCl/BiOBr,the agglomeration effect is reduced and the photodegradation reaction is more efficient.Figure 38 table 4 references 144...