Synthesis And Application Of Montmorillonite Supported BiOBr Composite Photocatalyst

Dye wastewater occupies a large proportion in industrial wastewater,and its harm to the environment is more and more serious.Dyestuff wastewater is complicated in composition,antioxidative,difficult to degrade,and has a great amount of water.Therefore,the development of efficient and economical wastewater treatment technology is the current research hotspot.Photocatalytic technology,as an efficient and safe environment-friendly environmental purification technology,has the advantages of simple equipment,high efficiency,low energy consumption,no secondary pollution,etc.,and has great potential and broad application prospects in industrial wastewater treatment.BiOBr catalyst was successfully synthesized by hydrothermal method using Bi?NO₃?₃·5H₂O,CTAB and glycol as raw materials.The visible light catalytic activity and photocatalytic mechanism of rhodamine B were investigated.In addition,semiconductor composite technology was used to prepare BiOI/BiOBr composite catalyst,effectively reducing the composite of BiOBr photogenerated electron-hole pairs,so as to improve the photocatalytic performance and catalytic activity of BiOBr.The photocatalytic properties and mechanism of the composite catalyst were also studied.As an important clay mineral,montmorillonite has a large specific surface area and porosity,abundant sources and low price,and is widely used as an adsorption material in wastewater treatment.Meanwhile,montmorillonite is also an excellent catalyst carrier.The loading of BiOI/BiOBr photocatalyst is a good solution to the problem that BiOI/BiOBr photocatalyst is difficult to recover in water.In this paper,calcium montmorillonite was used as the carrier of the composite catalyst,and the BiOI/BiOBr composite photocatalyst was partially inserted into the interlayer domain by taking advantage of the cationic exchangeable properties of its layered structure,so that the structural layer of montmorillonite was propped up,and the supported BiOI/BiOBr photocatalyst was obtained.XRD,uv-vis DRS,SEM,FT-IRand other test methods were used to characterize the montmorillonite nano-BiOI/BiOBr composite photocatalytic materials.The results showed that the dispersion degree and surface morphology of the catalyst changed to different degrees,and the corresponding surface reactivity changed accordingly.This is because the addition of montmorillonite minerals can significantly reduce the agglomeration phenomenon in the composite photocatalyst,and montmorillonite has a special layered molecular structure and excellent adsorption performance,which can make pollutants concentrate around the catalyst and increase the contact between the catalyst and organic pollutants,increase the photodegradation rate and improve the degradation effect.With the target degradation of Rhodamine B,catalyst dosing quantity is 0.01 g,under the condition of simulated visible light to illuminate 60 min,Rhodamine B degradation rate can reach more than 98%,after repeated 5 times,no obvious degradation rate drop,illustrate the preparated montmorillonite load BiOI/BiOBr composite photocatalytic materials not only have high photocatalytic activity,but also possess long service life and stable character.It is hoped that the results of this paper can provide some reference for the treatment of dye wastewater.