Construction And Photocatalytic Performance Of Hollow C-doped TiO₂ Composites Based On Glucose-derived Carbon Sphere

Photocatalytic degradation of organic pollutants by TiO₂ is an ideal solution for environmental pollution caused by antibiotics.However,antibiotic organic pollutants have stable chemical properties and are not easily degraded.In addition,large band gap width and poor charge separation efficiency make it difficult for TiO₂ to achieve efficient degradation of antibiotics under visible light.Therefore,to solve the problems of TiO₂-based photocatalysts with poor visible light response ability,insufficient redox active sites and low separation efficiency of charge carriers,glucose carbon spheres were used as templates and carbon sources to prepare C-doped TiO₂hollow spheres.Through further adjustment and modification,the effective removal of tetracycline under visible light was realized.The specific contents of research proposal are as follows:（1）Preparation and photocatalytic performance of hollow C-doped TiO₂ based on glucose-derived carbon sphereGlucose carbon spheres prepared by hydrothermal method were used as the substrate and carbon source.TiO₂ shells were coated on the surface of glucose carbon spheres by Sol-Gel method,and then calcined in air to obtain hollow C-doped TiO₂based on glucose-derived carbon sphere（CHTS）.By adjusting the calcination conditions,not only the C elements were successfully doped into the TiO₂ crystal,but also an appropriate crystal defect was constructed to achieve efficient degradation of tetracycline under visible light.The experiment of photocatalytic degradation of tetracycline show that the removal rate of tetracycline is 88.4%after 120 min under visible light irradiation,which is significantly higher than that of commercial TiO₂（P25）.（2）Construction and photocatalytic performance of CHTS@BiOBr nanosheets compositesBased on CHTS,CHTS@BiOBr nanosheets composites were prepared by depositing bismuth oxybromide（BiOBr）nanosheets on the surface of CHTS.The combination of CHTS and BiOBr can effectively improve the band gap width of the material,which can improve its visible light response ability.Moreover,heterojunction can be constructed to achieve effective spatial charge separation and inhibit electrons and holes recombination,and further improve the visible light photocatalytic activity.The experimental results show that the degradation rate of tetracycline reach 93.5%after 120 min under visible light irradiation,which is 5.1%higher than that of CHTS.（3）Construction and photocatalytic performance of CHTS@Bi₂O₃ nanoparticles compositesThrough evaporation deposition method,Bi³⁺was uniformly dispersed on the surface of CHTS,and CHTS@Bi₂O₃ nanoparticles composites（BCHTS）were prepared after calcined in air.The results show that Bi₂O₃ nanoparticles are finely and uniformly dispersed on the surface of CHTS,and the photocatalytic activity and stability of the material are greatly improved.The removal rate of tetracycline reaches97.5%under visible light irradiation for 120 min,while the removal rate of tetracycline is increased to 98.4%under visible light irradiation for 180 min.Considering the practical application,the experimental tests confirm that the prepared BCHTS has excellent cycling stability,and the removal rate of tetracycline still maintain 96.4%after 5 cycles.Under the irradiation of natural light,tetracycline can be completely removed within 60 min.The results show that the prepared BCHTS catalyst can be potentially used in actual application.