| With the increasing demand for human production and life,the global energy consumption is growing,facing the double crisis of energy shortage and environmental pollution.Therefore,how to solve the environmental and energy problems is imminent,which prompted the scientific workers to develop new efficient pollution control methods,in which the photocatalytic technology is a very promising research direction.In recent years,it has been found that bismuth oxybromide BiOX(X=Cl,Br,I)is also an efficient photocatalytic reactant,in which BiOBr is favored by the majority of researchers as narrow bandgap,unique electronic structure,good optical performance and photocatalytic performance.In this paper,Sb2O3/BiOBr and BiOBr were prepared by a simple low-temperature liquid-phase method and hydrothermal method.X-ray diffraction(XRD),scanning electron microscopy(SEM),UV-Vis(UV-Vis)and N2 adsorption-desorption were used to characterize the phase composition,surface morphology,optical properties and specific surface area of the samples.Rhodamine B(RhB)was used as a target of the simulation in visible light to evaluate its photocatalytic performance.The effects of Rh B initial pH on the photocatalytic performance of the bismuth oxide and its complex were also discussed.Finally,the photocatalytic mechanism of bismuth oxide and its complexes were also studied by trapping experiment,and the main active species affecting the photocatalytic activity of bismuth oxide and its complex were determined.The main reasearch conclusion were as follows:(1)In this paper,the degradation of RhB in the visible light was studied by combining Sb2O3 and Bi OBr which has a layered structure and excellent photocatalytic activity by low temperature liquid chromatography.The results showed that there was a good synergistic effect between Sb2O3 and BiOBr prepared by hydrothermal method,which may be related to the formation of heterojunction between Sb2O3 and BiOBr.At the same time,the doping of Sb2O3 promoted the generation of OH-on the surface of BiOBr,which resulted in the conversion of more h+ to ·OH,which reduced the recombination rate of photo-generated electron-hole.When the doping amount of Sb2O3 was 3%,The photocatalytic performance of the composite was the best.The complex played a dominant role in the photocatalytic degradation of RhB in visible light.The initial pH of 10 mg/L RhB had a high degradation rate and adsorption capacity between 2.5 and 4.7.The results showed that the composites had good stability and recyclability.(2)Microsphere BiOBr solid was prepared by simple hydrothermal method using mixed bromine source(CTAB、NaBr),Bi(NO3)2·5H2O as reactant and ethylene glycol aqueous solution as solvent.The results showed that the BiOBr photocatalytic activity prepared by mixed bromine source was superior to BiOBr prepared by single bromine source.n(CTAB):n(NaBr)=1:1,the photocatalytic activity of BiOBr was the best,and the degradation rate of Rh B reached 94.46% within 50 min,and the photocatalytic activity of BiOBr was increased by about 19.5%.This result can be attributed to the addition of CTAB to the presence of(110)crystal faces with higher activity.At the same time,the self-template effect of the appropriate CTAB maked the prepared microspheres BiOBr had a large specific surface area and contributed to the adsorption of organic matter,which significantly improved the photocatalytic activity of BiOBr.BiOBr microspheres had good stability and recyclability.When RhB initial pH was between 2.2 and 5.5,RhB can achieve better degradation effect.(3)Comparing the Sb2O3/BiOBr composite photocatalyst and BiOBr microsphere photocatalyst,we concluded that BiOBr microspheres exhibit great advantages both in laboratory and industrial production,and it showed great promising in industrial production and application. |
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