| As a new kind of photocatalyst,bismuth oxychloride(BiOCl)exhibits excellent photocatalytic performance due to its special layered structure and electronic properties has rapidly become a hotspot in the research of photocatalytic materials in recent years.However,BiOCl has a large bandgap and has a low utilization rate of solar energy,which seriously affects the practical application of BiOCl.Based on this,in order to broaden the photoresponse range of BiOCl,further improve the photocatalytic activity of BiOCl,thus to improve the practical application of BiOCl-based semiconductor photocatalytic materials in the field of organic wastewater treatment,this paper combines BiOCl with carriers with good conductivity or the photocatalytic semiconductor composites with band structure,BiOCl-based composite photocatalysts(BiOCl/sepiolite and BiOCl/Bi2WO6)were constructed,the properties and mechanism of photocatalytic degradation of BPA by composite photocatalytic materials were studied.The specific experiment contents are as follows:(1)A three-dimensional flower-like BiOCl/sepiolite photocatalyst was prepared by a simple hydrothermal method.The Morphology,crystal structure,light absorption characteristics,element valence,and specific surface area of composite photocatalysts were characterized by SEM,XRD,UV-Vis DRS,XPS,FT-IR and BET.The results show that due to the addition of sepiolite,the agglomeration of BiOCl is significantly inhibited,the specific surface area of the composite photocatalyst and the spectral response range are increased,and the recombination rate of the electron-hole pair is effectively reduced.(2)Using BPA as the target pollutant,the influence of different factors on the degradation rate of BPA was investigated.The experimental results show that when the content of sepiolite in the composite catalyst was 10%,the catalyst dosage was 1g/L,the pH value was 6,and the initial concentration of BPA was 10 mg/L,the degradation efficiency of BPA was better.The optimum photocatalytic ratio of the composite photocatalyst has high stability,and after repeated use 3 times,the degradation rate of BPA remains above 95%.(3)BiOCl/Bi2WO6 composite photocatalyst was prepared by hydrothermal method.The assynthesized samples were characterized by XRD,SEM,UV-vis,and BET.With BPA as the target pollutant,the catalytic activity of BiOCl/Bi2WO6 composite photocatalysts with different proportions was evaluated.The results show that both the catalytic activity and the stability of the composite photocatalyst have been greatly improved.(4)Free radical capture experiments were used to ascertain the reactive species in the degradation process of BPA.The results showed that three active species OH’,h+ and O2·-were involved in the degradation of BPA by the two composite photocatalysts.Among them,the contribution of BiOCl/sepiolite in the degradation of BPA was O2·->h+>OH·.The OH· plays a major role in the photocatalytic reaction of BiOCl/Bi2WO6 composite photocatalysts.(5)The GC-MS was used to test and analyze the intermediate products in the degradation of BPA in BiOCl/sepiolite composites,and the possible degradation pathway of BPA was inferred. |
