Preparation Of Bismuth-Based Visible Light Catalytic Material And Its Degradation Of Antibiotics

The current antibiotic pollution problem is becoming more and more serious,and antibiotic wastewater has an impact on human health,food safety,and sustainable de-velopment of environmental safety due to its toxicity,drug resistance,and low bio-chemical properties.Advanced oxidation technology based on persulfate has been proven to be one of the most effective processes for antibiotic wastewater treatment attribute to its high oxidation capacity,wide p H applicability range and mild operating conditions.Therefore,high activity,low cost and easy synthesis is the key to photocata-lytic degradation of antibiotics.Bismuth-based photocatalysts with the advantages of high stability,narrow band gap,low production cost,large pore size and photocorrosion resistance show excellent potential for application in the activation of peroxysulphate（PDS）process.This paper focuses on photocatalytic degradation of tetracycline hydro-chloride（TCH）.A series of bismuth-based catalysts were prepared by introducing ox-ygen vacancy（OVs）and constructing heterojunctions.The degradation laws and mech-anisms of Visible Light（Vis）/Catalyst（Cat）and Vis/Cat/PDS on pollutants were sys-tematically studied,and the specific research results are as follows:1)Bi₅O₇NO₃ with adjustable oxygen vacancy concentration was synthesized by an easy-to-operate solution combustion method.The introduction of OVs can regulate the band structure of Bi₅O₇NO₃,improve its electron-hole separation efficiency and visible light absorption ability,and promote its enhanced photocatalytic activity.Two cooperative catalytic degradation system（Vis/Cat and Vis/Cat/PDS）were constructed.Their photocatalytic performance was evluated,and the photocatalytic mechanism was investigated.Bi₅O₇NO₃ can be used to stimulate PDS under mild conditions,and the degradation rate of TCH can reach 83.79%in a short time through synergistic effect.Bi₅O₇NO₃ has cyclic stability,and can still reach more than 80%after four cycles of degradation rate.In addition,the Vis/Cat/PDS system showed excellent degradation ability for organic dyes,as well as other antibiotics.It shows that the system has some potential application for wastewater treatment.2)BiVO₄ with different light absorption capacity was synthesized by hydrother-mal method and solution combustion method.Bi₂S₃ couples with BiVO₄ phase to form S-scheme heterojunctions,which can exhibit excellent catalytic performance and redox ability.Under visible light irradiation,the degradation rate of 1:3 Bi₂S₃/BiVO₄ hetero-junction materials is 2.22 times and 5.44 times of that single-phase catalysts BiVO₄ and Bi₂S₃.And 1:3 Bi₂S₃/BiVO₄ was able to enhance its efficiency in degrading antibiotics with the help of activated PDS.Furthermore,the 1:3 Bi₂S₃/BiVO₄ composites showed excellent stability in both Vis/Cat system and Vis/Cat/PDS system cycle tests,which is important for the practical application of visible photocatalytic degradation of wastewater antibiotics.This paper provides a new approach for the construction of bismuth-based photo-catalysts with high catalytic activity and the ability to activate peroxysulphate,and also offers new ideas for the improvement of the reaction activity of photocatalytic degra-dation of antibiotics.