CeTiO4/g-C3N4复合材料的制备及其高效的光催化染料降解性能

采用简单固相法成功制备了CeTiO₄/g?C₃N₄?x(CTO/CN?x,x g为g?C₃N₄的添加量)复合材料,并通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)、N₂吸附-脱附测试、紫外可见吸收光谱(UV?Vis)及电化学测试对材料进行表征。研究发现:CeTiO₄与g?C₃N₄层状纳米片紧密复合,并成功构建了界面异质结结构;形成CTO/CN?x复合相的光催化材料具有良好的可见光光响应性能,且光生空穴-电子对的分离和迁移率明显提高;通过太阳光模拟不同样品光催化降解有机污染物罗丹明B,降解140 min后复合材料CTO/CN?6表现出最高的光催化活性,反应速率常数为0.0202 min^-1。其活性增强的主要原因是异质结结构的构筑降低了CTO光生载流子的复合几率,提高了光生载流子的迁移速率。

Preparation of CeTiO4/g-C3N4 Composite with Efficient Photocatalytic Activity for Dye-Degradation

The composite of CeTiO₄/g-C₃N₄-x (CTO/CN-x, x g was the addition amount of g-C₃N₄) was successfully prepared via a simple solid method synthesis. The as-synthesized catalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), N₂ adsorption-desorption test, X -ray photoelectron spectroscopy (XPS), UV -Vis diffuse reflectance spectra (UV -Vis DRS), and electrochemical test. It was found that CTO and CN layered nanoplates were closely combined to form heterostructure. CTO/CN-x composite photocatalyst exhibited outstanding visible light response, and it could improve the separation and mobility of photogenerated hole-electron pair. The photocatalytic activity of composite material was assessed by degradation of rhodamine B under simulated sunlight for 140 min. Compared to pure CTO and CN, CTO/CN-x composite showed the enhancement of photocatalytic activity, and the optimum reaction rate constant was 0.020 2 min^-1 for CTO/CN-6 (The addition amount of g-C₃N₄ was 6 g). The enhanced photocatalytic performance was mainly ascribed to the structure of heterostructure, which could reduce the recombination of CTO photocarriers and improve the transfer of photocarriers.