Preparation Of Photocatalytic Materials Based On TiO₂ And Research On Dye Degradation Performance

Organic dyes are the main reason for the deepening of the color of printing and dyeing wastewater.During the printing and dyeing process,about10%to 20%of the dyes are discharged into surface water as pollutants,reducing the transparency of water bodies and affecting human health.In order to improve the biochemical performance of printing and dyeing wastewater,This thesis uses TiO₂ as the base material,improves its photocatalytic performance by doping CdS and BiPO₄,discusses the influencing factors of photocatalytic degradation,and reveals the changes of Cd and Bi elements on the electronic transition energy of photocatalytic material TiO₂.The main conclusions are as follows:（1）CdS-TiO₂ was prepared by sol-gel method,and the prepared materials were characterized by XRD,UV-vis,SEM,etc.,which proved that CdS and TiO₂ were successfully doped and applied to the degradation of Rose Bengal B in printing and dyeing wastewater.Experimental results It shows that when the p H of the solution is 10.0,the doping amount of CdS is 0.50%,the calcining temperature of the catalyst is 500℃,and after calcining for 4 h,adding 1 mg/L to the printing and dyeing wastewater,the degradation rate of Rose Bengal B is 81.90%;By kinetic linear fitting,the CdS-TiO₂photocatalytic degradation of Rose Bengal B conforms to first-order kinetics,and the linear correlation R² is greater than 0.95;compared with the CdS-doped TiO₂ literature,the CdS-TiO₂ prepared in this paper degrades Rose Bengal B The effect is increased by 20%-40%,and the photocatalytic degradation activity is better than other preparation methods.（2）BiPO₄-TiO₂ was prepared by the sol-gel method,and the prepared materials were characterized by XRD,UV-vis,SEM,etc.,which proved that BiPO₄ and TiO₂ were successfully doped and applied to the degradation of Rose Bengal B in printing and dyeing wastewater.Experimental results It shows that when the solution p H is 10.0,the BiPO₄ doping amount is 0.50%,the catalyst calcination temperature is 500℃,and after calcination for 4 h,it is added to the printing and dyeing wastewater at a dosage of 1 mg/L,and the degradation rate of Rose Bengal B is 90.20%;By kinetic linear fitting,BiPO₄-TiO₂ photocatalytic degradation of Rose Red B conforms to first-order kinetics,and the linear correlation R² is greater than 0.95;compared with BiPO₄ doped TiO₂ literature,the BiPO₄-TiO₂prepared in this paper degrades rose The effect of red B is increased by 15%-30%,and the photocatalytic degradation activity is better than other preparation methods.（3）CdS-BiPO₄-TiO₂ was prepared by the sol-gel method,and the prepared materials were characterized by XRD,UV-vis,SEM,etc.,which proved that CdS was successfully doped and compounded with BiPO₄ and TiO₂ and applied to rose red in printing and dyeing wastewater,and the experimental results show that during compounding:when the p H of the solution is 10.0,the doping amount of CdS and BiPO₄ is 0.50%,the calcination temperature of the catalyst is 500℃,and after calcination for 4 h,it is added to the printing and dyeing wastewater at a dosage of 1 mg/L.The degradation rate of Rose Bengal B is 98.20%;by linear fitting of kinetics,the CdS-BiPO₄-TiO₂ photocatalytic degradation of Rose Bengal B conforms to first-order kinetics,and the linear correlation R² is greater than 0.95;compared with other double-doped TiO₂ documents In contrast,the CdS-BiPO₄-TiO₂ prepared in this paper has an increased degradation effect of Rose Bengal B by 5%-12%,and its photocatalytic degradation activity is better than other preparation methods.（4）Compare the effects of the three doped materials and TiO₂ by degrading Rose Bengal B.Experiments show that CdS-TiO₂,BiPO₄-TiO₂,CdS-BiPO₄-TiO₂ have better response to visible light,which is better than the other three photocatalytic materials;through kinetic linear fitting,the fitting constant（k）of CdS-BiPO₄-TiO₂ is 0.024 min^-1,cycle After 5 times of degradation of Rose Bengal B,the degradation rate reached 78.32%,still having good photodegradability.