In-Situ Construction Of Aluminum-Bismuth Photocatalysis Composites And Their Mechanism

Environmental pollution and energy shortage are two major international problems that need to be solved urgently.Photocatalysis technology has the advantages of environment-friendly,low price,sustainable resources and so on,which has considerable application prospects in solving the above problems.However,the current photocatalytic technology basically has the disadvantages of low efficiency of electron hole separation and low catalytic activity.In situ synthesis of heterojunction with high contact area and effective transfer of photogenerated carriers is an effective measure to solve the low separation efficiency.Using bismuth nitrate,aluminum nitrate,tetrabutylammonium bromide,urea and ethylene glycol as raw materials,bismuth oxybromide and alumina heterojunction(BiOBr/Al₂O₃)were prepared in situ by ionic liquid self ignition method to degrade rhodamine B(RHB).The photocatalytic activity of the heterojunction under simulated visible light and all light was tested by EDS,SEM,XRD,XPS,DRS,IR,IR,IR and so on The heterojunction photocatalyst was characterized by TEM,photocurrent and bright impedance.The results show that the activity of the composite photocatalyst is higher than that of the single bismuth oxybromide photocatalyst,and the highest photocatalyst activity is obtained when the ratio of raw material to bismuth nitrate:aluminum nitrate is 1:4.The reason is that the introduction of alumina can not only improve the specific surface area of the material,but also increase the concentration of oxygen defects.Based on the bismuth-rich bismuth oxyhalide photocatalyst,the effect is generally better than BiOX.After this article,the Bi₁₂O₁₇Br₂/Bi₂O₃/Al₂O₃ternary heterojunction was synthesized by the ionic liquid self-combustion method,and the heterojunction was tested under simulated visible light by degradation of Rh B And the photocatalytic activity under full light,and the photocatalytic reduction of CO₂activity was tested.SEM,TEM,XRD,XPS,PL,DRS,electrochemical testing and ESR were used to characterize the composition,structure and photo-generated carrier separation ability of the heterojunction.The results show that the synthesized bismuth-based catalyst heterojunction has better photocatalytic activity than a pure single bismuth-based catalyst.When the raw material is compared with bismuth nitrate:aluminum nitrate=8:1,the photocatalytic activity is the highest.The reason is The introduction of Al₂O₃promotes the ability of the heterojunction to adsorb oxygen and carbon dioxide.