Preparation Of Modified Perovskite Photohydrolysis Catalyst And Its Application In The Purification Of Printing And Dyeing Wastewater

Perovskite-type photocatalyst is widely used in photocatalytic wastewater treatment because of its simple preparation,high stability and good structure for modification.The common single-phase perovskite oxides have some disadvantages such as high photoelectron-hole recombination rate and low utilization efficiency,which limit their degradation in photocatalysis printing and dyeing wastewater.In this paper,the single-phase perovskite oxide La Ni O ₃ was modified and doped to prepare a photocatalyst with high photocatalytic activity,the degradation efficiency of methyl orange solution was investigated under different photocatalytic conditions.The main research of this paper is as follows:(1)Study on the performance of La Ni O₃ catalyst substituted by a-site element.A series of La_1-yBa_yNi O₃(y=0,0.1,0.2,0.3,0.4,0.5)catalysts were synthesized by sol-gel method with citric acid as complexing agent.The results of SEM,XRD and XPS show that the perovskite-type Oxides were prepared by doping the a site of L a Ni O₃.Photocatalytic degradation of Methyl Orange Solution under visible light irradiation was studied.The optimum doping ratio of a site B a²⁺on La_1-yBa_yNi O₃ photocatal yst was 0.1.The photocatalytic activity of La_1-yBa_yNi O₃ photocatalyst was doubled.The optimal conditions were determined by exploring the factors affecting the catalyst efficiency.The results showed that when the concentration of methyl orange was 10mg·L^-1,the p H value was 6,the irradiation time was120min and the dosage of photocatalyst was 1g·L^-1,the degradation efficiency of methyl orange was the highest 79.94%.(2)Study on the performance of L a Ni O₃ catalyst substituted by b-site elementsA series of La Ni _1-xCu_xO₃(x=0,0.1,0.2,0.3,0.4,0.5)catalysts were synthesized by sol-gel method with citric acid as complexing agent.The results of SEM,XRD and XPS show that the perovskite-type Oxides were prepared by doping the B site of La Ni O₃.The photocatalytic activity of La Ni_1-xCu_xO₃ photocatalyst for photocatalytic degradation of Methyl Orange Solution under visible light irradiation was increased by two times when the optimum doping ratio of Cu²⁺At B site was 0.1.The optimal conditions were determined by exploring the factors affecting the catalyst efficiency.The results showed that the highest degradation efficiency of methyl orange was 93.04%when the concentration of methyl orange solution was 10mg·L^-1,the p H value was 6,the irradiation time was 120min and the dosage of photocatalyst was 1g·L^-1.(3)Study on the performance of A/B codoped La Ni O ₃ catalystA series of La_1-yBa_yNi_1-xCu_xO₃(y=0,0.1,0.2,0.3,0.4,0.5)and(x=0.1)catalysts were synthesized by sol-gel method using citric acid as complexing agent.The results of SEM,X RD and XPS show that the perovskite-type Complex Oxides were prepared by doping the A and B sites of La Ni O₃ at the same time.The photocatalytic activity of La_1-yBa_yNi_1-xCu_xO₃ photocatalyst was increased by 2.15 times when the optimum doping ratio of Ba²⁺and Cu²⁺was 0.1 at the a site and B site of La_1-yBa_yNi_1-xCu_xO₃photocatalyst.The optimal conditions were determined by exploring the factors affecting the photocat alytic efficiency of photocatalyst.The results showed that the highest degradation efficiency of methyl orange was 96.79%when the concentration of methyl orange was 10mg·L^-1,p H value was 6,irradiation time was 120 min and the dosage of photocatalyst was 1g·L^-1.