Photocatalytic Degradation Of Bisphenol A By Visible-light Photocatalysts Based On Two-dimension BiOCOOH

Bisphenol A（BPA）is the main component of epoxy resins and polycarbonate plastics,which are widely used in everyday and industrial products.Because of its increasing demand and toxicological effects,Bisphenol A has been listed as the most concerned pollutant in water treatment.The presence of Bisphenol A has been recognized as A new problem in water and wastewater treatment and sediment recovery.Therefore,the removal of Bisphenol A and its derivatives from water and wastewater is a subject that must be studied.BiOCOOH is a promising N-type semiconductor photocatalyst.However,due to BiOCOOH’s narrow light response range and rapid recombination of photoelectron-hole pairs,its photocatalytic activity and practical application are greatly limited.Therefore,this thesis through the study of the modification of BiOCOOH,uses many kinds of modification methods of combination of strategy,the two-dimensional economic efficiency is prepared ultrathin BiOCOOH photocatalytic composite material,realize the efficient removal of Bisphenol A in water,for highly active photocatalyst Bifoundation design provides a new train of thought,is expected to repair make a significant contribution in the aquatic environment.Firstly,two-dimensional ultrathin BiO（HCOO）_xI_1-x solid solution nanosheets were successfully prepared by combining the two modification methods of two-dimensional ultrathin structure and solid solution formation.Controllable preparation of the catalyst was achieved by regulating the dosage of potassium iodide and sodium formate.A novel two-dimensional ultrathin BiO（HCOO）_xI_1-x solid solution photocatalytic system was proposed to eliminate Bisphenol A.It was found that as an optimal ratio of BiO（HCOO）_0.75I_0.25,BPA could be entirely removed within 30 min irradiation.The synergistic effect between the ultrathin morphology and the hybrid structure was verified by several optical and photoelectric experiments.BiO（COOH）_xI_1-x nanosheets have high VBM position,wide VL adsorption range and high photocharge separation rate,resulting in significant photocatalytic performance and efficient degradation of Bisphenol A.It was found that O₂^·-and h⁺play key roles in BiO（COOH）_xI_1-x/VL system by free radical trapping experiments,and the corresponding catalytic oxidation mechanism was proposed.In addition,the possible degradation pathway of Bisphenol A was proposed.In order to further enhance the removal efficiency of Bisphenol A,the heterojunction structure was derived on the basis of two-dimensional ultra-thin BiO（HCOO）_xI_1-x solid solution,and different ratios of Ag Br/BiO（HCOO）_0.75I_0.25 heterojunction photocatalyst were prepared.The visible light degradation experiment was carried out with bisphenol A as the target pollutant.And determine its optimal ratio.Within 20min of visible light irradiation,the degradation rate reached more than 80%.Among them,10%Ag Br/BiO（HCOO）_0.75I_0.25 showed the best photocatalytic efficiency,and BPA removal rate reached 100%.The mechanism analysis shows that Ag Br and BiO（HCOO）_0.75I_0.25 form a Z-type heterojunction,which promotes the separation of photoexcited carriers,enriches the generation pathway of active substances,and further improves the photocatalytic ability.