【作者】 仲松涛； 周慧； 高强； 沈明；

【Author】 Songtao Zhong;Hui Zhou;Qiang Gao;Ming Shen;School of Chemistry & Chemical Engineering,Yangzhou University;

【机构】 扬州大学化学化工学院；

【摘要】 作为新一代非金属聚合物光催化剂,石墨相氮化碳（g-C₃N₄）具有独特的二维结构和可见光活性,在水的分解、对有机污染物的降解和重金属离子去除等领域显示出了巨大的潜力。BiOI具有较窄的禁带宽度（1.7-1.9 eV）,因此在可见光区域具有强吸收和较高光催化活性。本文结合g-C₃N₄和BiOI两种半导体材料的优点,通过简单回流法-稀碱刻蚀合成g-C₃N₄/BiOI/Bi₂O₂CO₃纳米复合材料。该方法具有可大规模、低温、制备时间短等优点。稀碱刻蚀使BiOI表面覆盖薄薄一层Bi₂O₂CO₃从而形成原位异质结,这有利于电子空穴对的高效分离。从透射电镜图片可以看出BiOI呈薄片状附于g-C₃N₄片层之上,同时很清晰的看出BiOI薄片表面部分被碱刻蚀后变得更粗糙,这意味着材料的比表面积增大,会具有很好的可见光催化性能。光催化实验表明,25 min该复合材料对罗丹明B的降解效率可达到98.1%。光催化作用机理可以通过瞬时光电流测试、活性物种捕获实验和EPR测试来解释。更多还原

【Abstract】 As a new generation of metal-free polymeric photocatalysts,graphitic carbon nitride （g-C₃N₄）own a unique two-dimensional structure and visible light activity.BiOI has a narrow band gap（1.7-1.9 eV）,hence it has strong absorption and high photocatalytic activity in the visible light region.In this paper,g-C₃N₄/BiOI/Bi₂O₂CO₃ nanocomposites were synthesized by simple reflux method and surface etched treatment considering the advantages of g-C₃N₄ and BiOI semiconductor materials.The preparation method has the advantages of large scale,low temperature and short preparation time.Dilute alkali etched treatment made the surface of BiOI covered with a thin layer of Bi₂O₂CO₃ to form in-situ heterojunction,which is beneficial for the efficient separation of electron-hole pairs.The TEM image in Fig.1 showed that the BiOI nanosheets are well coupled with the g-C₃N₄ layers.Meanwhile,it is obvious that the surface of the BiOI nanosheets became rougher after etched,which means larger specific surface area and higher photocatalytic activity.The photocatalytic experiment showed that the degradation efficiency of Rhodamine B could reach98.1%after 25 min.The mechanism of photocatalysis can be explained by transient photocurrent measurements,active species capture experiment and EPR test.更多还原