Research On Synthetic Process Of Bi-O-X Photocatalyst

Semiconductor photocatalytic materials have very good application prospects in environmental pollution control.Traditional photocatalytic materials,such as TiO ₂,belong to wide band gap semiconductors,which have low utilization of sunlight.Therefore,for the research of semiconductor photocatalyst,on the one hand,the traditional photocatalyst is modified,on the other hand,the development of new photocatalyst.Bismuth semiconductor photocatalytic materials have attracted much attention due to their unique layered structure and stable physical and chemical properties.As a new type of photocatalyst,bismuth halide?Bi-O-X,X=C l,Br,I?is a new type of photocatalyst.Due to its internal unique layered structure,an electric field is produced inside the semiconductor.The existence of the electric field can inhibit the recombination of the photoelectron-hole pairs and improve the photocatalytic activity of the catalyst.In this study,Bi₁₂O₁₇Cl₂ and Bi₃O₄Cl were synthesized by solid phase reaction.The effects of calcining temperature and ball milling on the phase,morphology and photocatalytic properties of synthetic photocatalyst were studied.The BiO Br was synthesized by sol-gel method.The photocatalyst were focused on influence of the calcination time on the morphology and photocatalytic properties.The synthesized products were characterized and analyzed by XRD,SEM,TEM,UV-Vis diffuse reflectance and optical activity evaluation system.It was showed that the phase of the photocatalyst synthesized by ball milling and grinding and milling at 500?is purer than 600?of layered Bi₁₂O₁₇Cl₂ and Bi₃O₄Cl prepared by solid phase synthesis.And both of those photocatalyst could have absorbtance in the range of visible light,and the band gap is about 2.25 e V and 2.65 e V,respectively.In addition,the degradation rate of methyl orange was higher with the catalyst synthesized under 500?and 600?,the degradation rate was 97%/150 min,96%/110 min which shows a higher photocatalytic activity.When BiO Br prepared by sol-gel method,the BiOBr photocatalyst obtained after 3 hours roasting has a good absorption in the range of visible light,the band gap is about 2.88 eV.