Design And Application Of BiOCOOH-based Photocatalytic Materials

Although the continuous development of society and science technology has greatly improved people's life,it is followed by severe environmental pollution problems.Among them,the problem of water pollution is particularly prominent.Due to the many shortcomings of traditional water pollution treatment methods,scholars are committed to finding new and efficient technologies for energy conservation.In particular,semiconductor photocatalytic technology can use clean and renewable solar energy,thus owning broad application potential.Bi OCOOH has significant research significance in the fields of photocatalysis and environmental governance due to its unique layered structure and green harmless characteristics.However,due to its low efficiency in using visible light,the application development of Bi OCOOH is limited.Based on Bi OCOOH,this paper improves its visible-light catalytic performance by constructing heterojunction.The main work of the study is as follows:?1?We successfully prepared a plate-to-plate Bi₂Mo O₆/Bi OCOOH heterojunction photocatalyst by a simple solvothermal method.Through X-ray diffraction?XRD?and scanning electron microscopy?SEM?observations,it was found that with the addition of sodium molybdate raw material,the morphology and structure of the composite also changed.The photocatalytic results show that the incorporation ratio of Bi₂Mo O₆has a significant effect on the performance of heterojunction photocatalysts.The apparent rate constant of optimal sample for Levofloxacin degradation was 11.3 and 241.3 times higher than that of pure Bi₂Mo O₆and Bi OCOOH,respectively.Tests such as photoluminescence spectroscopy?PL?show that the main reason for the improved performance is that the heterojunction formed between the two components promotes the separation of charges.Cyclic experiments show that the sample has stable catalytic activity and structural stability.In addition,the results of free radical capture studies indicate that holes?h⁺?and superoxide radicals?·O₂^-?are the main free radicals for degradation of levofloxacin.?2?Bi OBr/Bi OCOOH p-n heterojunction photocatalysts were fabricated via a two-step solvothermal method.The photocatalytic performance of as-prepared heterojunctions was evaluated under visible light for the degradation of Levofloxacin.The composite samples exhibited significantly accelerative degradation rate compared to both pure catalysts?Bi OBr and Bi OCOOH?.Among them,the best sample of levofloxacin degradation was Bi OBr/Bi OCOOH molar ratio of 1:1,and the degradation rate under visible light reached 90.1%after 40 minutes.Its apparent rate constant of the optimal sample for Levofloxacin degradation was 1.7 and 144.8 times higher than that of pure Bi OBr and Bi OCOOH.The DRS test shows that the light absorption edge of the BOB/CH-3 composite has a significant red shift compared to CH?about 365 nm?,and the visible light response area of the BOB/CH-3 is enlarged.Through the research of Motty-Schottky and transient photocurrent,etc.,the increased activity can be attributed to the Bi OBr/Bi OCOOH material is a p-n heterjunction,and the built-in electric field formed by it inhibits the electron-hole pair recombination.Furthermore,quenching experiment was also carried out.The results indicated that the photogenerated hole?h⁺?and superoxide radical?·O₂^-?were the dominant reactive radicals responsible for the degradation of Levofloxacin.