| The combination of various advanced oxidation processes?AOPs?has attracted continuous attention of researchers due to its advantages of high efficiency,simplicity and low cost in treating pollutants in environmental water bodies.Among them,the photo-Fenton catalysis technology,which combines the advantages of photocatalysis and Fenton catalysis to remove organic pollutants in wastewater.Bi2WO6 as photocatalytic material has attracted extensive attention in photocatalytic wastewater treatment appropriate band gap energy,low cost and good catalytic performance.However,it still has the disadvantages of low utilization rate of visible light and high recombination rate of photogenerated electrons and holes.This limits its large-scale industrial application.In this paper,a heterogeneous photo-Fenton catalyst is constructed by combining Bi2WO6 with transition metal oxides and sulfides with Fenton-like catalytic performance to form a semiconductor heterojunction.The structure,morphology,optical properties,energy band structure and degradation mechanism of the samples were analyzed by using XRD,XPS,SEM/TEM,EDX,UV-Vis-DRS,VB-XPS,PL,TR-PL,ESR and other testing techniques,respectively.,and finally its photocatalytic activity and Fenton catalytic activity are enhanced synergistically by using enhanced electron-hole separation capability and accelerated rapid reduction capability of high-valence metal to low-valence metal.The main conclusions of this paper are as follows:Firstly,the two-dimensional Bi2WO6 nanosheets were prepared by a simple one-step hydrothermal method,in which sodium tungstate,bismuth nitrate and cetyltrimethylammonium bromide were used as precursors.Amorphous zero-dimensional Fe OOH quantum dots?QDs?-decorated Bi2WO6 nanosheets heterostructure?Fe OOH/Bi2WO6?was successfully prepared by room temperature impregnation method.The electron spin resonance spectroscopy confirmed that·OH and O2-were the main active species to promote the degradation of organic pollutants.The results show that the synergistic effect of Fe OOH and Bi2WO6 can promote the fast transfer of photogenerated electrons from Bi2WO6 to Fe OOH quantum dots and accelerate the reduction of Fe?III?to Fe?II?by photogenerated electrons,thus improving the photo-Fenton catalytic activity of Fe OOH/Bi2WO6 composite catalyst.Secondly,the 2D/2D CuS/Bi2WO6 heterostructure was successfully constructed by a in-situ assembly strategy.The type-II heterojunction promotes the separation efficiency of photo-generated carriers in the catalyst.At the same time,the surface coupling of Bi2WO6 and CuS significantly accelerates the circulation of Cu?II?to Cu?I?,improves the stability of CuS in Fenton reaction,and further improves its catalytic activity.Thirdly,the type-II CuCo2S4/Bi2WO6 heterojunction was designed and constructed using a secondary solvothermal method for photo-Fenton degradation of tetracycline hydrochloride?TC-HCl?.This unique 2D/2D heterojunction can effectively promote the separation and transfer of photo-generated carriers and further promote the reduction of Co?III?to Co?II?,thus realizing efficient photo-Fenton catalytic activity.Fourthly,a novel Cu2Zn Sn S4/Bi2WO6?CZTS/BWO?2D/2D type-II heterojunction was successfully synthesized by the secondary solvothermal method.Photocatalytic activity results show that the prepared CZTS/BWO heterojunction has excellent photocatalytic performance for Rh B degradation.In addition,the addition of hydrogen peroxide?H2O2?can further improve its catalytic performance.Finally,based on the band structure of the catalyst,the photo-Fenton catalysis mechanism of the catalyst system was explored. |
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