溶胶-凝胶法制备BiFeO_3薄膜及其光催化性能研究

Photocatalytic properties of BiFeO_3 thin films fabricated by sol-gel method

采用溶胶-凝胶法在Si/SiO_2衬底上制备了多铁性材料BiFeO_3薄膜。分别用X射线衍射,扫描电子显微镜以及紫外-可见分光光度计和光催化实验来测试并研究了薄膜的晶体结构,表面形貌以及紫外-可见吸收光谱和光催化降解效果。实验结果显示,所有的BiFeO_3薄膜呈钙钛矿结构,其中温度为550℃退火处理的薄膜结晶性较好,表面也较均匀,无空隙生成;BiFeO_3薄膜能较好地吸收可见光并对不同浓度的亚甲基蓝溶液都有较好的光催化活性,对浓度为20mg/L亚甲基蓝溶液有很好的降解效果,说明降解的污染物的浓度也会对BiFeO_3薄膜的光催化效率产生一定的影响。

A multiferroic material BiFeO 3 thin film was fabricated on Si/SiO 2 substrate by sol-gel method. X ray diffraction, scanning electron microscope, ultraviolet visible spectrophotometer and photocatalysis experiment were used to test and study the crystal structure, surface morphology, UV-Vis absorption spectrum and photocatalytic degradation effect of the films. The experimental results show that all BiFeO 3 thin films had perovskite structure. The films annealed at the temperature of 550 ℃ had better crystallinity, more uniform surface and no interspace. Meanwhile, BiFeO 3 films could absorb visible light well and had better photocatalytic activity for different concentrations of methylene blue solution. The BiFeO 3 film had a good degradation effect for the methylene blue solution with the concentration of 20 mg/L. The result indicated that the concentration of degraded pollutants also had a certain effect for the photocatalytic efficiency of BiFeO 3 thin film.