复合铌酸盐的合成和光催化活性的研究

Preparation and Photocatalytic Activities of Niobate Composites

利用光催化剂降解有机染料具有很好的应用前景,光催化材料在光催化反应中起着重要的作用,但是如何制备化学性质稳定、在可见光下具有高的催化活性的催化剂一直是人们探索的一个主题。以Ag2O、Nb2O5、Na2CO3为前驱物,经高温固相反应法合成了具有不同Na/Ag摩尔比的(AgNbO3)1-x(NaNbO3)x复合铌酸盐。采用X-射线粉末衍射(XRD)、紫外-可见漫反射谱(UV-vis DRS)等方法对样品的结构和光谱响应特征进行了表征,以亚甲基蓝的降解反应为探针考察不同Na/Ag摩尔比的(AgNbO3)1-x(NaNbO3)x复合铌酸盐在可见光下的光催化活性。结果表明,由高温固相法合成出的复合铌酸盐的结构随着Na/Ag摩尔比的变化而变化,光谱响应特征随Na/Ag摩尔比的减小逐渐红移,而对亚甲基蓝的降解性能随Na/Ag呈规律性变化,其中(AgNbO3)0.6(NaNbO3)0.4复合铌酸盐呈现最好的光催化活性。

Photocatalytic degradation by using organic dye has good prospects.The photocatalytic material plays an importan role in process of dye photocatalytic degradation,however it has been an interesting topic how to prepare photocatalytic materials with high chemical stability and excellent catalytic activity under visible light irradiation.The niobate composites [（AgNbO3）1-x（NaNbO3）x] were synthesized by a solid-state reaction method,and Ag2O、Nb2O5 and Na2CO3 were used as precursors.The structure and spectral response characteristics were characterized by means of powder X-ray diffraction（XRD） and ultraviolet visible diffuse reflectance spectroscopy（UV-vis DRS）,and the photocatalytic activity of the niobate composites were evaluated by degradation reaction of methylene blue under natural light.The results showed that the structure of niobate composites change with different Na / Ag molar ratio,and the spectral response existed red shift with the decreases Na / Ag molar ratio,which led to photocatalytic activity to degradation of methylene blue vary with Na/Ag ratio.It was found that（AgNbO3）0.6（NaNbO3）0.4 niobate composite showes the highest photocatalytic activity to degradation of methylene blue.