氧化银-钽酸钠复合光催化剂的制备及光催化处理染料废水的研究

采用钽酸盐中的n型半导体光催化剂NaTaO3作为主要研究对象,与另外一种具备可见光响应性能的p型半导体光催化剂Ag2O复合,采用高温水热反应法制备纳米氧化银-钽酸钠异质结复合光催化剂,并使用SEM,UV-vis DRS,EDS等分析方法对其进行表征。在此基础上,以罗丹明B水溶液作为模拟染料废水,探讨所制备复合材料在可见光条件下处理模拟染料废水的可行性及最佳反应条件。实验结果表明,通过水热法能够制备出具有优异可见光催化活性的Ag2O/NaTaO3复合光催化剂,在波长大于400 nm的光照条件下光催化活性良好,Ag2O与NaTaO3质量比为1∶1时,模拟废水初始浓度10 mg/L,体积50 mL,光催化剂用量50 mg,pH=7,温度25℃,光照3.0 h,模拟染料废水降解率为66.75%,复合Ag2O后的NaTaO3具备了可见光波段的光催化性能。

In this study,the n-type semiconductor photocatalyst NaTaO3 was used as the main research object,and it was combined with another p-type semiconductor photocatalyst Ag2O with visible light response performance,the nano sodium tantalum oxide-silver oxide was prepared by high-temperature hydrothermal reaction,and characterized by SEM,UV-vis DRS,XRD,and other analytical methods.Based on these analyses,the rhodamine B aqueous solution was chosen as the simulated dye wastewater,and the feasibility and optimal reaction conditions of the as-prepared composites for the treatment of simulated dye wastewater under visible light irradiation were discussed.As the results demonstrated,the Ag2O/NaTaO3 composite photocatalyst with excellent visible light photocatalytic activity can be prepared by hydrothermal method.The photocatalytic activity is good under the illumination condition of wavelength greater than 400 nm,and the best performance is obtained at the mass ratio of Ag2O to NaTaO3 is 1:1,the initial concentration of the simulated wastewater is 10 mg/L,the volume is 50 mL,the dosage of the photocatalyst is 50 mg,pH=7,and the temperature is 25℃,after 3 hours of illumination,the degradation rate of simulated dye wastewater was 66.75%.It was concluded that sodium tantalum oxide which is combined with Ag2O attained photocatalytic property in visible light.