The Preparation And Performance Research Of Barium Ferrite Composite Photocatalyst

With the rapid development of industry,environmental pollution has become increasingly serious.Photocatalytic technology uses clean,renewable solar energy to stimulate semiconductor materials and realize photocatalytic oxidation-reduction reactions under mild conditions,which is of great significance for solving energy crisis and environmental problems.At present,the traditional monomer photocatalyst has the disadvantages of wide band gap and low visible light utilization,which limits its application.Therefore,the development of photocatalysts with advantages of high efficiency,low cost,environmental protection,magnetic recovery,etc.has broad application prospects in the field of sewage treatment and air purification.Among them,magnetic-supported composite photocatalyst has become a research hotspot in the field of photocatalysis due to its advantages of being recyclable and reusable.In this paper,BaFe₁₂O₁₉ is used as a doping substance to carry out a series of composite modification work and to construct BaFe₁₂O₁₉/g-C₃N₄,BaFe₁₂O₁₉/Ag₃PO₄,BaFe₁₂O₁₉/AgBr composite photocatalysts.The X-ray diffraction?XRD?,scanning electron microscopy?SEM?,photoelectron spectroscopy of X-ray?XPS?and other characterization methods were used to analyze the structural composition and the catalytic activity of the composite photocatalyst was systematically investigated through the degradation of rhodamine B?RhB?,bisphenol A?BPA?and methyl orange?MO?under the condition of visible light.In addition,The mechanism was explored by fluorescence spectroscopy?PL?,electrochemical tests,and reactive group testing.The specific research content of this paper is as follows:1.BaFe₁₂O₁₉/g-C₃N₄ composite photocatalyst was synthesized by the calcination method.The composition,structure and optical magnetic properties of the obtained composite photocatalysts were analyzed by XRD,TEM,IR,XPS,DRS,VSM and other characterization methods.TEM results showed that the BaFe₁₂O₁₉ nanosheets were successfully loaded on the surface of g-C₃N₄ and the combination of them was stable.The XPS results showed a chemical shift of nitrogen,indicating an interaction between BaFe₁₂O₁₉ and g-C₃N₄.In the photocatalytic degradation experiment,we controlled the light conditions,H₂O₂,temperature and other conditions,and analyzed their influence on the photocatalytic reaction.The results show that BaFe1₂O₁₉/g-C₃N₄ composite photocatalyst have a photo-Fenton and thermal catalytic role,embodied in its under visible light irradiation and no light can activate H₂O₂degradation of RhB,BaFe₁₂O₁₉ load of 16.8%of Ba Fe₁₂O₁₉/g-C₃N₄ showed the highest photocatalytic activity,and it has good photochemical stability.At the same time,Ba Fe₁₂O₁₉/g-C₃N₄composite photocatalyst has good magnetic separation properties,which can be recovered and recycled conveniently and quickly under the effect of external magnetic field.2.The BaFe₁₂O₁₉/Ag₃PO₄ composite photocatalyst was synthesized by hydrothermal method.The structure of the prepared catalyst was characterized by XRD,SEM,EDS,XPS,DRS,VSM and other means.Composition,optical and magnetic separation properties were characterized.The photocatalytic activity experiments show that the photocatalytic activity of BaFe₁₂O₁₉/Ag₃PO₄ composite photocatalyst on BPA shows as the BaFe₁₂O₁₉ mass fraction increases.According to the enhancement rule,10%BaFe₁₂O₁₉/Ag₃PO₄ composite photocatalyst showed the best photocatalytic activity.After 30 min irradiation,the degradation efficiency of BPA was 79%.The experimental results show that the photocatalytic stability of BaFe₁₂O₁₉/Ag₃PO₄ composite photocatalyst is higher than that of monomer Ag₃PO₄.ESR and hydrogen peroxide?H₂O₂?detection experiments showed that there was a photo-Fenton reaction in the Ba Fe₁₂O₁₉/Ag₃PO₄ system,and the results were based on the capture experiment results.The possible reaction mechanism is to construct an in-situ photo-Fenton catalyst with magnetic separation performance.3.In order to effectively improve the stability and recyclability of the catalyst,a BaFe₁₂O₁₉/AgBr composite photocatalyst was synthesized by a two-step method.The composition and structure of the composite photocatalyst were analyzed by XRD,SEM,XPS and other characterization methods.The DRS spectra showed that with the increase of BaFe₁₂O₁₉ mass fraction,the light absorption intensity of the composite photocatalyst also increased,which is consistent with the color change tendency of the catalyst.VSM results show that the composite photocatalyst has magnetic separation performance.Under visible light irradiation,the photocatalytic activity of methyl orange?MO?as the target pollutant was analyzed.The results show that BaFe₁₂O₁₉/AgBr composite photocatalyst can degrade the dye MO,and the degradation rate is almost unchanged after cycling reaction.This shows that the introduction of BaFe₁₂O₁₉ can improve the photocatalytic activity and light stability of AgBr.