Preparation And Its Photocatalytic Properties Of Bismuth Oxide Based Heterojunction

Bismuth oxide（Bi₂O₃）,as a semiconductor photocatalyst,can effectively absorb visible light,but it still has some problems in the application process,such as low separation efficiency of photoelectron-hole pair and fast recombination rate.In view of the above shortcomings,this paper constructed three bismuth oxide base photocatalytic composites ofα-Bi₂O₃/Bi₅O₇I/Bi OI,α-Bi₂O₃/Cd S,andβ-Bi₂O₃/Bi OI by electrophoretic deposition to solve the above problems.Theα-Bi₂O₃/Bi₅O₇I/Bi OI composites were obtained by electrophoretic deposition.XRD,TEM,PL,UV-vis DRS,EIS,mott-schottky were used to characterize.The composites photocatalyst were obtained by controlling the amount of I₂,the transformation fromα-Bi₂O₃ to Bi₅O₇I and then to Bi OI was realized to formα-Bi₂O₃/Bi₅O₇I/Bi OI.The microstructure ofα-Bi₂O₃/Bi₅O₇I/Bi OI was honeycomb.PL characterization showed that composites effectively inhibit photo-generated carrier recombination.Electrochemical tests showed thatα-Bi₂O₃/Bi₅O₇I/Bi OI composites had higher carrier concentration and faster separation rate.After the cyclic degradation of acid fuchsin byα-Bi₂O₃/Bi₅O₇I/Bi OI composites（C4）for 50 times under simulated sunlight irradiation,diffraction peaks ofα-Bi₂O₃was disappeared,but the photocatalytic degradation efficiency still reach more than80%,indicating that the high photocatalytic activity is caused by Bi₅O₇I/Bi OI.Theα-Bi₂O₃was obtained by sol-gel method and Cd S was obtained by water bath method,α-Bi₂O₃/Cd S composites were obtained by different molar ratios.XRD,SEM,PL,Raman,FT-IR,UV-vis DRS,EIS were used to characterize.The uv-visible diffuse reflectance spectrum showed that the visible light response range ofα-Bi₂O₃/Cd S composites increased.EIS testing showed that the migration rate of electrons inα-Bi₂O₃/Cd S composites increased.The results of degradation of methyl orange（MO）in BC45 samples under simulated sunlight showed that the photocatalytic degradation efficiency was 87%,57%higher than that ofα-Bi₂O₃.The photocatalytic degradation efficiency of acid fuchsin dye was 81%,57%higher than that ofα-Bi₂O₃.Theβ-Bi₂O₃was obtained by calcination method,and different proportions ofβ-Bi₂O₃/Bi OI composites were obtained by different amount of I₂by electrophoretic deposition method.Theβ-Bi₂O₃ could be directly converted to Bi OI with I₂ at 25 V.XRD,SEM,PL,UV-vis DRS,EIS were used to characterize.PL characterization indicated thatβ-Bi₂O₃/Bi OI composites could effectively inhibit electron-hole pair recombination.UV-vis DRS indicated thatβ-Bi₂O₃/Bi OI composites increased the visible light absorption range.The photocatalytic of acid fuchsin dye degradation efficiency ofβ-Bi₂O₃/Bi OI（D3）composites still over 75%after 50 times under visible light irradiation,no diffraction peak disappeared,indicating thatβ-Bi₂O₃/Bi OI has good stability and reusability.