Investigation Of Fabrication,Modfication,Characterization And Photocatalysis Activity Of Bismuthyl Bromide

In this work,the as-prepared catalysts were characterized by X-ray diffraction(XRD),Brunauer-Emmett-Teller(BET)surface area,UV-visible diffuse reflectance spectroscopy(UV-vis DRS),transmission electron microscopy(TEM),Fourier transformed infrared(FTIR),field emission scanning electron microscopy(FESEM)and X-ray photoelectron spectroscopy(XPS),and X-ray fluorescence spectroscopy(XRF).The photocatalytic activity of photocatalysts is evaluated using the decomposition of RhB solution as a model reaction.The BiOBr nanosheets have been prepared with a UV irradiation assisted synthesis methods.The UV irradiation leads to the change of atomic chemical environment and the change of the surficial electron density in the synthetic process.At the same time,the catalysts with UV irradiation assisted synthesis broaden the visible absorption,shortened the band gaps and increased of specific surface area.In addition,we have find that the solvent has important influence on the synthesis.Ethanol as solvent,the average grain size of the samples is smaller than that of the sample using water as solvent.Degradation of rhodamine B using ethanol as solvent is better than water as solvent.We have prepared two kinds of nonmetal modified BiOBr through the hydrothermal method with thiourea,phosphate as sulfur and phosphorus sources,respectively.Modification of S and P made BiOBr crystal cell increase.We have find that P modified BiOBr appeares BiP04 phase,and S modified BiOBr exhibits not only strong visible light adsorption ability but also a large specific surface area,while the P modified BiOBr shows inferior the visible light absorption and a small specific surface area.S modification of BiOBr in degradation process shows the best photocatalytic activity,the effect of P modification of BiOBr photocatalytic is not ideal.Based on the results of the previous chapter,we have explored different sulfur content modification of BiOBr further,and found the best addition amount of sulfur.S modified BiOBr materials have been prepared by simply solvothermal synthesis method.S incorporation to catalyst exposed {001} face,the appropriate content of sulfur could increase the specific surface area of the catalyst and lead to the red shift of visible light absorption spectrum,incorporation of S effectively improves the efficiency of separation of electron hole pair,thus improve the photocatalytic activity.